TERRY, Associate Judge:
Appellee Tinker sued the District of Columbia for injuries allegedly suffered in the course of an arrest. A jury awarded him $500,000 in damages. During the pre-trial phase of the case, the trial court denied the District of Columbia’s motion for leave to amend its answer by asserting the statute of limitations as a defense, and denied the District’s motion for summary judgment based on the statute of limitations. On appeal from the final judgment, the District contends that these pre-trial rulings were erroneous. We agree, reverse the judgment, and remand for further proceedings as outlined in part IV of this opinion.
I
A. Facts underlying Tinker’s claim
The following statement of facts is based on the testimony at trial, viewed in the light most favorable to Tinker. It appears from the verdict that the jury substantially accepted Tinker’s version of what happened.
On the evening of September 10, 1988, Joseph Tinker, an automobile mechanic, was walking from his home on Yuma Street, S.E., toward Ninth Street, on his way to a convenience store. He had left his house without a wallet or any identification. In his back pocket Tinker was carrying a knife with a four-inch blade which he used for stripping [59]*59wires in the course of his work. While walking along Yuma Street, Tinker stopped and picked up a plastic toy gun which was lying on the ground.
After crossing Ninth Street, Tinker heard the sound of people running and brakes squealing, and then he heard someone order him to halt. Turning around, he was hit and knocked down by a Metropolitan Police officer. As he lay on the ground, the officer threatened him with his service pistol and hit him with his nightstick. The officer then pulled Tinker to his feet and began to search him. Upon discovering the knife in his back pocket, the officer again shoved Tinker to the ground, handcuffed him, pulled him once again to his feet, and placed him under arrest. In the course of these events, Tinker’s right shoulder and wrist were seriously injured.
Once in custody, Tinker was taken to the Seventh District police station. While being processed there, he complained of his injuries and was taken to District of Columbia General Hospital, where he later underwent extensive surgery on his right shoulder. He stayed in the hospital, and then in the infirmary at the jail, for about a month.
B. Facts relevant to the statute of limitations issue
Upon his release from the hospital, Tinker was charged with possession of a prohibited weapon, namely, the knife that he had been carrying in his pocket. He pleaded guilty to this charge on December 6, 1988, and at a later date he was sentenced to serve nine months in prison.1
For reasons not entirely clear from the record, Tinker was mistakenly released from Lorton Reformatory on August 11, 1989. Soon thereafter, however, the District of Columbia Board of Parole issued a warrant for his arrest, stating that he was on parole from an earlier sentence for robbery and that the Board had information that he was in violation of his parole. He was re-arrested on September 15, 1989, and returned to Lorton to complete the remainder of his robbery sentence. On July 14, 1990, Tinker was transferred to a halfway house, and on September 28, 1990, he was again released on parole.
On July 19, 1991, Tinker filed a three-count civil action against the District of Columbia, seeking redress for the injuries he had allegedly suffered as a result of his arrest on September 10, 1988.2 On August 23 the District filed its answer denying the substantive allegations in the complaint. Five months later, on January 24, 1992, the parties filed a stipulation stating that “the issue of excessive force is one within the ken of the jury and will not be presented through expert testimony by either the plaintiff or the defendant.”
On April 13, 1992, the District filed a motion for leave to amend its answer by adding a claim that the assault count was barred by the statute of limitations. In a memorandum filed in support of this motion, the District stated (1) that the initial omission of the statute of limitations defense in its answer was inadvertent, (2) that relevant case law “provides that leave to amend shall be freely given,” and (3) that Tinker would suffer “no prejudice attributable to the timing of the request for amendment.” A few weeks later, on May 27, the District filed a motion for summary judgment on the assault claim, arguing that it was barred by the statute of limitations. Tinker opposed both motions, and the court denied them both in a nine-page order.
Some time later the case was tried before a jury, which awarded Tinker $500,000 in damages. The District moved for a judgment notwithstanding the verdict, which the court denied. This appeal followed.
[60]*60II
In denying the District’s motion for leave to amend its answer by adding a statute of limitations defense, the trial court gave three reasons. First, the court ruled that because discovery had already been completed, Tinker would be substantially prejudiced if the District were allowed to amend its answer. Second, the court concluded that the District’s delay of approximately eight months in asserting this defense was “inexcusable,” since the District was experienced in trying many cases of a similar nature, and the availability of a statute of limitations defense should have been recognized much earlier. Third, the court held that the District had “impliedly waived this defense [by taking] the affirmative step of joining with the plaintiff in filing a stipulation” that expert witnesses need not be called to testify on the issue of excessive force. Because the stipulation “speaks directly to how the parties will proceed on this count in the complaint,” the court said, “the District surely was on notice of the details of the allegation” and should have “realized the time sequence of all events involving the assault and the filing of this lawsuit.” On appeal the District contends that the trial court’s denial of its motion was an abuse of discretion.
Super.Ct.Civ.R. 8(c) states that the statute of limitations is a defense which must be raised affirmatively by a defendant in a responsive pleading. If not pleaded promptly, this defense may be deemed waived by the trial court. Whitener v. Washington Metropolitan Area Transit Authority, 505 A.2d 457, 458 (D.C.1986). On the other hand, Rule 8(f) mandates that pleadings be construed so as to do “substantial justice,” and has been consistently interpreted to reflect “a preference for resolution of disputes on the merits, not on technicalities of pleading.” Id. (citation omitted). Additionally, Rule 8 must be read in light of Rule 15(a), which provides that parties may amend their pleadings with leave of court after a responsive pleading is filed, and that such leave “shall be freely given when justice so requires.”
When reviewing a trial court order denying a party leave to amend a pleading, this court must determine whether that denial was an abuse of discretion. In Eagle Wine & Liquor Co. v. Silverberg Electric Co., 402 A.2d 31 (D.C.1979), we said that although motions for leave to amend are not to be granted automatically, “[t]he discretion accorded the trial court in deciding a motion for leave to amend is to be considered together with the prevailing spirit of liberalism in allowing such amendments when justice will be so served.” Id. at 34 (citations omitted).
Guided by these general principles, we consider the trial court’s ruling on the District’s motion to amend its answer.
In January 1992 both parties filed with the trial court a written stipulation which said:
It is stipulated and agreed that at the trial of the above captioned case the issue of excessive force is one within the ken of the jury and will not be presented through expert testimony by either the plaintiff or the defendant. The lack of such expert testimony at trial will result in no grounds for a directed verdict being requested or granted by either the plaintiff or the defendant on that issue.
Almost three months later, the District filed the motion for leave to amend its answer by adding a statute of limitations defense. In its subsequent order, the trial court held that, by agreeing to the stipulation, the District had addressed the merits of the case to such an extent that there was “utterly no way” for the District to account for its failure to realize that a statute of limitations defense might be available. Calling this “a major lapse on the part of the District,” the court found the lapse “inexcusable” and denied the motion.
The court’s reliance on the parties’ stipulation as a basis for its ruling was, in our view, an abuse of the discretion vested in it by Rule 15(a). This court has held that unless there is prejudice to the opposing party, the rules of procedure cannot bar a defendant from raising the defense of the statute of limitations even after the filing of its answer. Whitener v. WMATA, supra, 505 A.2d at 460. In the present case, therefore, the trial court could not properly deny [61]*61the District’s motion simply because the parties had entered into a stipulation about expert testimony. There was nothing in the stipulation to suggest that the District had waived its right to raise the affirmative defense of the statute of limitations. Thus it was incumbent on Tinker to make a showing of prejudice resulting from the District’s failure to raise the defense earlier; without such a showing, the motion for leave to amend should have been granted.
The trial court stated in its order that one significant reason for denying the District’s motion was that “the length of delay [in asserting the statute of limitations] is truly inexcusable, particularly since the District of Columbia is accustomed to defending large numbers of similar cases, filed by persons who are imprisoned for several years and who frequently do not pursue their cases while incarcerated.” But whether the delay was excusable or inexcusable is really beside the point; the only issue here is whether the delay resulted in prejudice to the opposing party. “[D]elay—even lengthy delay—by itself will not usually provide sufficient ground for refusal to allow an amendment_' Refusals to grant amendments on the grounds of ‘lateness’ or ‘delay alone properly may be reversed.” Eagle Wine & Liquor, supra, 402 A.2d at 35 (citation omitted). Thus the trial court’s reliance on the District’s delay would be warranted only if that delay had caused substantial prejudice to Tinker. We conclude that it did not.
The trial court reasoned that Tinker would suffer substantial prejudice if the District were allowed to amend its answer because “[a]ll parties have gone through the entire discovery period. Time and expense [have] been committed by plaintiff.” The court’s inquiry should have been more narrowly focused. In Whitener, for example, we considered such factors as whether the statute of limitations defense “was readily apparent from the face of the complaint,” whether the plaintiffs had elected to “forego any other avenue of relief in reliance on [the defendant’s] failure to plead the statute,” and whether the plaintiffs had incurred (or would incur) any undue litigation expense as a result of the defendant’s failure to plead the statute of limitations earlier. See 505 A.2d at 460. Had the court done so here, it could not have found prejudice substantial enough to justify denial of the District’s motion to amend.
The defense of the statute of limitations was readily apparent from the face of Tinker’s complaint, which stated that the alleged assault—an intentional tort with a one-year statute of limitations—occurred on September 10, 1988, almost three years before he filed suit. Thus Tinker must have known from the start that he was proceeding, at least on the assault count, in the face of a known procedural peril, and the District’s lateness in bringing the matter up did not change that fact. Tinker effectively conceded this point in his opposition to the District’s motion for summary judgment:
Certainly, from the plaintiffs complaint it was patently obvious that more than one year had expired from the assault and battery committed upon him on September 10, 1988, and the filing of his civil action on June 19, 1991.
Thus we agree with the comment in the District’s brief that Tinker “cannot claim that he was unfairly surprised by the District’s assertion of the defense.”3
At the heart of Tinker’s case is the assertion that he would have suffered substantial prejudice if the motion had been granted because he withdrew his claims of negligent hiring, training, and supervision, as alleged in Count I of the complaint, “because of the defendant’s stipulation to the lay issue of excessive force.” In other words, Tinker is saying that because of the stipulation, he dropped what would have been the only remaining viable claim in his ease, namely, his claim of negligence against the District. As the District points out, however, the first and third counts of the complaint were not withdrawn by Tinker until several months after the trial court denied the District’s motion to [62]*62amend, and even longer after the stipulation about expert testimony. This sequence of events fatally undermines Tinker’s only colorable claim of significant prejudice.
The fact that the parties entered into the stipulation about excessive force — which was alleged only in the second count of the complaint, the one which ultimately went to trial 4 — in no way prevented Tinker from investigating, developing, and ultimately litigating the merits of the two additional counts alleging negligence and medical malpractice on the part of District personnel. While it is understandable that Tinker (or any plaintiff) might prefer to litigate a simple and inexpensive theory of liability rather than a more complicated and costly one, that choice inhered in the case as it was pled in the complaint. It was not created by the District’s entering into a reasonable stipulation about expert testimony, nor was it the result of the District’s tardiness in seeking to plead the statute of limitations. When Tinker decided not to go forward on the first and third counts of his complaint after the stipulation was agreed upon, he did so with full knowledge of the District’s effort to assert the statute of limitations on the intentional tort claim. In any event, the disposition that we order in part IV, infra, affords him adequate relief from any arguable prejudice.
We therefore hold that the trial court abused its discretion in denying the District’s motion to amend its answer.
III
The trial court also ruled in the alternative that the District’s motion for summary judgment, based on the statute of limitations, must be denied on the merits. D.C.Code § 12-302(a) (1995) provides, in part, that if “a person entitled to maintain an action” is imprisoned at the time the right of action accrues, he or she “may bring action within the time limited after the disability is removed” — i.e., after being released from imprisonment. In this case, however, the court ruled that because Tinker had been temporarily released from prison in error, that “brief break” in his incarceration was “legally invalid [and] should be regarded as a nullity for all ... legal purposes.” The court therefore held that his erroneous release in August 1989 did not cause the statute to start running, and that under D.C.Code § 12-302(a) the statute was tolled until his final, lawful release in September 1990 — less than a year before he filed his complaint. We hold that this ruling was error and that the statute began to rim irrevocably when Tinker was initially released in August 1989.
Before considering the merits, we must address a procedural point. Citing Morgan v. American University, 534 A.2d 323, 325-329 (D.C.1987), Tinker argues that the trial court’s denial of the District’s motion for summary judgment may not be reviewed on appeal from the final judgment entered after a full trial on the merits. Morgan does so hold, as a general rule, but Morgan also recognizes that “any legal rulings made by the trial court at summary judgment affecting [the] final judgment can be reviewed” on appeal after an adverse jury verdict. 534 A.2d at 327 (citation and internal punctuation omitted; emphasis added). This principle is applicable here, for the legal issue involving the statute of limitations was in no sense subsumed within the factual issues presented to the jury. In addition, we note that during the trial, at the close of the plaintiffs case, the District made a motion for directed verdict, “the first ground” of which was a renewal of its earlier motion for summary judgment. Although the discussion thereafter focused mainly oh the stipulation and whether the District had complied with it, we are satisfied that the renewal of the earlier motion by way of a motion for directed verdict was sufficient to preserve the issue for appellate review, as Morgan itself teaches. See id. at 327 (denial of motion for directed verdict, incorporating grounds of earlier motion, is “of course appealable after an adverse jury verdict” (citation omitted)). We therefore hold that the [63]*63denial of the District’s earlier motion “is properly before us pursuant to the general rule that appeal from a final judgment calls into question all of the interlocutory rulings leading up to it.” Bulin v. Stein, 668 A.2d 810, 813 n. 6 (D.C.1995) (citation omitted).
In any event, we have already held that the trial court abused its discretion in denying the District’s motion for leave to amend its complaint. The necessary result of that holding is that the judgment must be reversed and the case remanded with directions to allow the amendment. Once the complaint is amended, the District would be entitled to renew its motion for summary judgment based on the statute of limitations, and that motion, for the reasons we shall now explain, would have to be granted.
A The applicable statute of limitations
Preliminarily, we must decide whether Tinker’s assault claim is subject to a one-year or a three-year statute of limitations. D.C.Code § 12-301(4) sets a one-year limit on the time within which a plaintiff may file a civil action for assault and battery. D.C.Code § 12-301(8), on the other hand, states that the time for filing suit based on a cause of action “for which a limitation is not otherwise specifically prescribed,” which includes most negligence claims, “is three years.” If the three-year statute applies here, the District cannot prevail, for it is undisputed that Tinker’s complaint was filed less than three years after the date of his injury.
Tinker, citing our decision in Etheredge v. District of Columbia, 635 A.2d 908 (D.C.1993), contends that he presented a claim of “assault and battery — excessive force” which contained within it elements of both negligence and assault. As a result, he maintains, this particular claim was subject to the three-year statute of limitations, D.C.Code § 12-301(8). Etheredge, in our view, does not support Tinker’s argument.5 The dispositive case here is not Etheredge but Maddox v. Bano, 422 A.2d 763 (D.C.1980).
In Maddox, as in the case at bar, the plaintiff alleged both assault and battery and negligence by police officers in effecting an arrest. The one-year statute of limitations for assault and battery had run before the complaint was filed, but the three-year statute for negligence had not. We affirmed a summary judgment in favor of the District, holding that a claim alleging excessive force involved only assault and battery, not negligence:
Appellant’s complaint described an injury received as a consequence of excessive force alleged to have been exercised by the arresting officers. There is no dispute that the physical contact was intentional, and such intentional contact constitutes battery.... The only tortious conduct clearly pled is assault and battery. The terms “carelessly and negligently” are con-elusory assertions, and without more the complaint does not raise a cognizable claim of negligence.... Moreover, the trial court was not bound by plaintiffs characterization of the action.
Id. at 764-765 (citations omitted).
In the present case, as in Maddox, the gravamen of the second count of Tinker’s complaint was that the conduct of the arresting police officer on September 10, 1988, amounted to assault and battery. Throughout the trial, the testimony of the witnesses concerned only whether Tinker had suffered any injuries that were deliberately inflicted by that officer. At no time did Tinker even attempt to prove negligence on the part of [64]*64any police officer or other District employee.6 Moreover, our eases make clear that “excessive force” is a term of art denoting an act of assault or battery by law enforcement officials committed in the course of their duties. E.g., Allison v. United States, 623 A.2d 590, 594 (D.C.1993); Jackson v. District of Columbia, 412 A.2d 948, 956 (D.C.1980). Nothing in the case law even hints at an element of negligence, or a tort distinct from assault and battery.
Thus we conclude that the only tortious conduct alleged in the second count of the complaint and proved by Tinker at trial was assault and battery on the part of the police. It follows that his claim was subject to the one-year statute of limitations, D.C.Code § 12-301(4).
B. Was the statute tolled?
Thus we come to the central issue in this case: whether the statute of limitations was tolled throughout Tinker’s two separate periods of incarceration, or whether the tolling ended, and the statute began to run, when Tinker was released from prison, supposedly on parole, in August 1989.
Although the parties disagree on the validity of Tinker’s initial release, they do agree, and the record shows, that he was released from prison on August 11, 1989, and remained free for more than a month, until at least September 15, 1989.7 D.C.Code § 12-302(a)(3) tolls the statute of limitations when a plaintiff is “imprisoned ... at the time the right of action accrues.” In the District of Columbia, a cause of action generally accrues when the plaintiff suffers an injury — in the present case, on September 10, 1988. See Brown v. Jonz, 572 A.2d 455, 456 (D.C.1990). There is no dispute that the statute was tolled by section 12-302(a)(3) from the moment of Tinker’s arrest on September 10. See Cannon v. District of Columbia, 569 A.2d 595, 596 (D.C.1990). Finally, it is clear that a release from incarceration stops the tolling and re-starts the running of the statute of limitations. Id.
Both parties contend that this case turns on the validity of Tinker’s August 1989 parole. The District, calculating the length of Tinker’s sentence in light of statutorily mandated good-time credits, argues that this initial parole was lawfully granted. Thus the District concludes that since Tinker was legitimately paroled, the statute of limitations began to run on August 11, 1989. Tinker, on the other hand, asserts that his affidavit (see note 7, supra) demonstrated that his initial parole was invalid, as the trial court ruled, and that the statute of limitations did not begin to run until his valid parole in September 1990. The record does not conclusively establish whether the August 1989 parole was valid or invalid, but we conclude, for the reasons which follow, that the validity vel non of that parole is irrelevant.
Although the tolling issue presented here is one of first impression in the District of Columbia, other courts have held that an inmate’s release from incarceration, whether valid or invalid, irrevocably starts the statute of limitations running as to any cause of action accruing at the time of his or her arrest. Moreover, and crucially for this case, the statute is not tolled again if the inmate is re-arrested. Burrell v. Newsome, 883 F.2d 416, 420 (5th Cir.1989);8 Kaiser v. Cahn, 510 F.2d 282, 286 (2d Cir.1974);9 Stephens v. [65]*65Curtis, 450 F.Supp. 141, 144 (S.D.Tex.1978); cf. Simpson v. D.C. Metropolitan Police Department, 789 F.Supp. 5, 8 (D.D.C.1992) (allegation that plaintiff was continuously incarcerated by either District or federal authorities created issue of fact as to possible tolling under D.C.Code § 12-302(a)(3), even though ease for which he was initially arrested was dismissed for want of prosecution). The rationale for such a holding is set forth in cases such as Hamil v. Vidal, 140 Ill. App.3d 201, 488 N.E.2d 1024, 94 Ill.Dec. 777 (1985):
A careful reading of the applicable statute here reveals that the limitations period is tolled only for that period of imprisonment during which the [tort] occurs, not during subsequent periods of incarceration. This is reasonable because once a prisoner is released ... nothing prevents the plaintiff from commencing his action at that time.
Id. at 204, 94 Ill.Dec. at 779, 488 N.E.2d at 1026.10
Further, Tinker has cited no authority whatever to support his contention that because his initial parole was allegedly invalid, the statute of limitations was tolled until his subsequent lawful parole. The cases on which he relies say nothing about the tolling of a statute of limitations. They hold only that a prisoner mistakenly released from custody, although allowed to count his time on release toward the completion of his sentence, must nonetheless be returned to prison to serve out the remainder of his sentence when the mistake is discovered. Leonard v. Rodda, 5 App. D.C. 256, 275 (1895); White v. Pearlman, 42 F.2d 788, 789 (10th Cir.1930); Carson v. State, 489 So.2d 1236, 1238 (Fla.1986); People v. Cavelli, 50 N.Y.2d 919, 921, 409 N.E.2d 924, 925, 431 N.Y.S.2d 450, 451 (1980). Those decisions do not help us resolve the issue presented here.
Therefore, regardless of the validity of Tinker’s initial release from custody in August of 1989, the fact remains that at that instant his disability of imprisonment was removed. Thus he was immediately able to pursue his claim against the District, and the time within which the law allowed him to do so — i.e., the statute of limitations — began to run at the moment of his release. Tinker has cited no case, and we have found none, supporting his argument that the statute was tolled anew upon his re-arrest five weeks later. Consequently, the statute of limitations expired on August 11, 1990, almost a year before Tinker filed this suit in June 1991. See Burrell v. Newsome, supra, 883 F.2d at 420 (citing cases).
IV
When an appellate court reverses a trial court ruling which it deems erroneous, the usual effect of the reversal is to return the parties to the position in which they were situated at the time of the erroneous ruling. See Hessey v. Burden, 615 A.2d 562, 569-570 (D.C.1992) (citing eases). In this case, however, a simple reversal will not achieve that goal. In his opposition to the District’s motion to amend its answer, Tinker asked the court, if it granted the motion, to “allow him time for additional discovery and to name an expert in police practices and procedures.” In making this request, Tinker was obviously looking ahead to a possible trial on counts I and III of his complaint. After the court denied the District’s motion to amend, however, Tinker voluntarily dismissed those counts, leaving only count II to be tried. In the particular circumstances of this case, we think it appropriate to restore the status quo at the time of the erroneous ruling.
Accordingly, we hold that the trial court abused its discretion in denying the District’s motion to amend its answer by adding the defense of the statute of limitations, and that it legally erred in denying on the merits the District’s motion, based on the statute of limitations, for summary judgment on count II of the complaint. In addition, exercising our power under D.C.Code § 17-306 (1989) to do what is “just in the circumstances,” we [66]*66vacate the dismissal of counts I and III, reinstate those counts, and remand the case so that the trial court may rule on Tinker’s request for additional discovery. The judgment is reversed, and the case is remanded for further proceedings consistent with this opinion.
Reversed in part, vacated in part, and remanded.