BRIGHT, J.
*625
Pursuant to statute (§ 31-294c [b] ), "an employer who fails to contest liability for an alleged injury ... on or before the twenty-eighth day after receiving a written notice of claim and who fails to commence payment for the alleged injury ... on or before such twenty-eighth day, shall be conclusively presumed to have accepted the compensability of the alleged injury ...." The plaintiff, Marcella Woodbury-Correa, appeals from the decision of the
*255
Compensation Review Board (board) affirming the decision of the Workers' Compensation Commissioner (commissioner), denying the plaintiff's motion to preclude
the defendant, her employer, Reflexite Corporation, from contesting liability for the repetitive trauma injuries claimed and noticed on her form 30C.
On appeal, the plaintiff claims that the board (1) exceeded its authority by making new factual findings that contradict the findings made by the commissioner, and (2) erred in affirming the commissioner's denial of the motion to preclude the defendant from contesting liability for the plaintiff's repetitive trauma injuries. We agree with both claims and reverse the decision of the board.
We begin with the underlying facts as found by the commissioner, as well as the procedural history and uncontested facts as revealed by the record. On April 17, 2009, the plaintiff had an existing employment relationship with the defendant. On that date, she filled out a form 30C claiming repetitive trauma injuries, the
*626
symptoms of which, she alleged, began in 2003. She sent the form 30C via certified mail on April 18, 2009, both to the defendant and to the Workers' Compensation Commission (commission). Both the commission and the defendant received the form 30C on April 20, 2009. The defendant did not file a proper and timely form 43 to dispute liability.
On February 24, 2014, pursuant to General Statutes § 31-294c (b), the plaintiff filed a motion to preclude the defendant from contesting liability for her repetitive trauma injuries. Nearly one year later, on January 5, 2015, the defendant filed a written objection to the plaintiff's motion on the ground that it had filed a form 43 in a timely manner.
The commissioner found that the commission file reflected that "there were never any claims for indemnity or medical benefits for the [plaintiff]," and that the "first claim for benefits was ... some five years after the claimed date of injury." The commissioner, thereafter, concluded that it was "impossible for the [defendant] to comply with the statutory requirements to issue any benefit payments during the [twenty-eight] day period following the filing of the [plaintiff's] form 30C as no benefits were claimed," and, on that basis, he denied the plaintiff's motion to preclude the defendant from contesting liability. The plaintiff filed a petition for review of
*256
the commissioner's decision with the board.
*627
A hearing was held before the board on March 18, 2016. In a June 22, 2016 written decision, the board affirmed the commissioner's decision denying the plaintiff's motion to preclude the defendant from contesting liability, specifically agreeing, in part, that the defendant was not able to file a timely form 43 due to "impossibility." This appeal followed. Additional facts will be set forth as necessary.
Before reviewing the plaintiff's claims, we set forth the applicable standard of review. "The commissioner has the power and duty, as the trier of fact, to determine the facts ... and [n]either the ... board nor this court has the power to retry facts .... The conclusions drawn by [the commissioner] from the facts found [also] must stand unless they result from an incorrect application of the law to the subordinate facts or from an inference illegally or unreasonably drawn from them .... [Moreover, it] is well established that [a]lthough not dispositive, we accord great weight to the construction given to the workers' compensation statutes by the commissioner and review board .... Cases that present pure questions of law, however, invoke a broader standard of review than is ordinarily involved in deciding whether, in light of the evidence, the agency has acted unreasonably, arbitrarily, illegally or in abuse of its discretion .... We have determined, therefore, that the traditional deference accorded to an agency's interpretation of a statutory term is unwarranted when the construction of a statute ... has not previously been subjected to judicial scrutiny [or to] ... a governmental agency's time-tested interpretation .... Furthermore, [i]t is well established that, in resolving issues of statutory construction under the [Workers' Compensation Act (act), General Statutes § 31-275 et seq. ], we are mindful that the act indisputably is a remedial statute that should be construed generously to accomplish its purpose .... The humanitarian and remedial purposes of the act counsel against an overly narrow construction that unduly limits eligibility for workers'
*628
compensation .... Accordingly, [i]n construing workers' compensation law, we must resolve statutory ambiguities or lacunae in a manner that will further the remedial purpose of the act .... [T]he purposes of the act itself are best served by allowing the remedial legislation a reasonable sphere of operation considering those purposes ....
"Our scope of review of the actions of the board is similarly limited .... The role of this court is to determine whether the review [board's] decision results from an incorrect application of the law to the subordinate facts or from an inference illegally or unreasonably drawn from them." (Citations omitted; internal quotation marks omitted.)
Wiblyi
v.
McDonald's Corp.
,
168 Conn. App. 77
, 84-86,
144 A.3d 1075
(2016).
"In deciding a motion to preclude, the commissioner must engage [in] a two part inquiry. First, he must determine whether the employee's notice of claim is adequate on its face. See General Statutes § 31-294c (a). Second, he must decide whether the employer failed to comply with § 31-294c either by filing a notice to contest the claim or by commencing payment on that claim within twenty-eight days of the notice of claim. See General Statutes § 31-294c (b).
If the notice of
*257
claim is adequate but the employer fails to comply
*629
with the statute, then the motion to preclude must be granted." (Footnote altered; internal quotation marks omitted.)
Id., at 86-88
,
144 A.3d 1075
.
I
The plaintiff claims that the board exceeded its authority by making a new factual finding concerning the form 43 that contradicts the finding made by the commissioner, despite the fact that the commissioner's finding had not been challenged on appeal to the board. She argues that the board acted improperly "when it liberally construed the unambiguous factual finding of the commissioner that 'a proper and timely form 43 was not filed by the [defendant]' to mean that 'the form 43 that was filed was not "proper" [because] it was not "timely." ' The board not only inserted a new factual finding into the commissioner's decision, but [it] deleted the commissioner's original finding that the defendant failed to properly serve the commission with a form 43 in accordance with its statutory mandate." We agree.
*630
In his findings, the commissioner specifically found that "[e]vidence produced at the formal hearing as well as the contents of the commission's file indicate that a proper and timely form 43 was not filed by the [defendant]." The commissioner cited, as support for this finding, several exhibits. The commissioner was not requested to correct this finding, and neither party challenged this finding on appeal to the board. Moreover, although the finding was not preserved for review, an examination
*258
of the exhibits cited by the commissioner readily confirms that this finding was not clearly erroneous. The plaintiff properly filed a form 30C claiming repetitive trauma injuries, as found by the commissioner, which was received both by the board and by the defendant on April 20, 2009. On May 5, 2009, the defendant sent its form 43, via certified mail, to the plaintiff's attorney, as evidenced by the return receipt. The defendant did not serve the commission with its form 43 at that time. Instead, on July 24, 2009, despite the requirements of General Statutes § 31-321
and form 43,
the defendant sent, via
facsimile transmission
, its form 43 to the commission.
The board, in its written decision, attacked the argument of the plaintiff's attorney that the "commissioner
*631
found that the [defendant] never filed a form 43 with the ... commission as required by the act. Therefore, statutory preclusion must lie." (Internal quotation marks omitted.) The board opined that the statement of the plaintiff's attorney was "unequivocally factually incorrect [in that the defendant] did file a form 43 contesting the claim which was received by the commission on July 24, 2009, a date more than [twenty-eight] days after the claimant filed her form 30C seeking benefits but well within the one year safe harbor period to contest the extent of disability .... The trial commissioner in [his] findings ... found that the [defendant] had not filed 'a
proper and timely
form 43.' ... We suggest that the trial commissioner inartfully expressed ... in [his] findings ... that the form 43 that was filed was not 'proper' as it was not 'timely.' To suggest in pleadings before this commission, and indeed again at oral argument before this tribunal, that a form 43 had
never
been filed by the [defendant], or that the evidence presented would support such a factual finding by the trial commissioner, is a distortion of the facts on the record." (Citations omitted; footnote omitted; emphasis in original.) The board thereafter proceeded to review the plaintiff's appeal as though the commissioner had found that the defendant's form 43 had been filed untimely with the commission, but, nonetheless, properly filed. We agree with the plaintiff that this was in error.
The commissioner clearly found that "a proper and timely form 43
was not filed
by the [defendant]." (Emphasis added.) The plaintiff's attorney had argued to the board that the commissioner had found that the defendant had never filed a form 43 with the commission
as required by the act
. A review of the commissioner's findings reveals that the argument of the plaintiff's attorney was accurate and not "a distortion of the facts on the record." The
*259
defendant improperly and untimely
*632
sent its form 43 to the commission in a facsimile transmission. As indicated by the commissioner's decision, a proper form that complied with the act was not filed by the defendant. Form 43 and § 31-321 do not contain any language that permits the filing of a form 43 by facsimile transmission to the commission; rather, both the form and the statute require that it must be filed either in person, by registered mail, or by certified mail. See
Dubrosky
v.
Boehringer Ingelheim Corp.
,
145 Conn. App. 261
, 274,
76 A.3d 657
("[i]t is well settled that notice provision under the [act] should be strictly construed" [internal quotation marks omitted] ), cert. denied,
310 Conn. 935
,
78 A.3d 859
(2013). The record provided to us on appeal contains no properly filed form 43.
Accordingly, we agree with the plaintiff that the board improperly changed a finding of the commissioner and relied on that changed finding in its decision.
II
The plaintiff next claims that the board erred in affirming the commissioner's denial of the motion to preclude the defendant from contesting liability on the basis of the defense of "impossibility." Specifically, she argues that the defense of impossibility, as articulated in
Dubrosky
v.
Boehringer Ingelheim Corp.
, supra,
145 Conn. App. at 269-70
,
76 A.3d 657
, is not applicable when an employer contests liability rather than the extent of disability. She contends that if an employer chooses to
contest liability
for the employee's injuries, it must file a proper
*633
and timely form 43, regardless of whether the employee submitted medical bills within twenty-eight days of the employee's filing of form 30C. We agree.
The following additional facts aid in our analysis. The commissioner concluded that there was no evidence that the plaintiff had "claimed either medical or indemnity benefits for her alleged injuries during the [twenty-eight] day period following the filing of the form 30C," and that because the plaintiff had not submitted a claim for any benefits during that time, "[i]t was impossible for the respondents to comply with the statutory requirements to issue any benefit payments during [that twenty-eight] day period ...."
In her appeal to the board, the plaintiff argued that the commissioner improperly concluded that the defense of impossibility
*260
applied in this case and that it improperly denied her motion to preclude the defendant from contesting liability. She contended that the commissioner was required to grant her motion because he found that the defendant had failed to file a proper and timely form 43, as is required by § 31-294c (b), to contest liability.
The board affirmed the commissioner's decision, concluding in relevant part that "[t]he [plaintiff] simply did not proffer a credible argument that subsequent to filing her form 30C, the [defendant] failed in [its] obligation to respond, and, therefore, the 'safe harbor' under
*634
Dubrosky
[v.
Boehringer Ingelheim Corp.
, supra,
145 Conn. App. at 269-70
,
76 A.3d 657
] was in effect [because] the [defendant] filed a form 43 within the one year period provided ... under § 31-294c .... In the present case, the trial commissioner found that there had been no event subsequent to the [plaintiff] filing the form 30C to which the [defendant] could have reacted and determined [its] 'safe harbor' was in place."
The plaintiff argues that the board improperly found that the defendant properly had filed a form 43; see part I of this opinion; and it improperly concluded that the commissioner correctly determined that the "safe harbor" provision articulated in
Dubrosky
applied to cases in which an employer was attempting to contest
liability
rather than to contest the
extent of disability
. We agree.
In
Dubrosky
, the dispositive issue was whether the employer was precluded from contesting
the extent of a disability
under § 31-294c (b) because it had been impossible for it to have commenced payment of compensation within the statutory twenty-eight day time period because no medical bills had been submitted to it during that time period.
Dubrosky
v.
Boehringer Ingelheim Corp.
, supra,
145 Conn. App. at 263
,
76 A.3d 657
; see generally
Harpaz
v.
Laidlaw Transit, Inc.
,
286 Conn. 102
, 130,
942 A.2d 396
(2008) (under § 31-294c (b), if employer neither timely pays nor timely contests liability, conclusive presumption of compensability attaches and employer is barred from contesting employee's right to receive compensation on any ground or extent of employee's disability). Unlike the present case, the defendant employer in
Dubrosky
did not contest liability; it contested only the extent of the plaintiff's disability.
Dubrosky
v.
Boehringer Ingelheim Corp.
, supra, at 266,
76 A.3d 657
.
*635
The plaintiff in
Dubrosky
fell during a work related business call on January 9, 2009, and injured his knee. Id., at 264,
76 A.3d 657
. He reported the injury to his supervisor on January 12, 2009, but did not seek immediate medical attention or miss time from work.
Id.
More than one month later, on February 18, 2009, the plaintiff filed a form 30C seeking compensation for the injury to his knee. Id., at 265,
76 A.3d 657
. Beginning on February 27, 2009, the plaintiff began seeking medical treatment from various providers, but the defendant did not begin receiving bills for the plaintiff's injury until June, 2009, which bills it paid.
Id.
On October 20, 2009, the defendant employer filed a form 43 contesting the plaintiff's claim.
Id.
The defendant also filed a motion to dismiss the claim, and the plaintiff filed a motion to preclude the defendant from contesting
liability and the extent of disability
. Id., at 266,
76 A.3d 657
. At a January 31, 2011 hearing, the defendant withdrew its motion to dismiss and
accepted the plaintiff's claim
, but it argued that it should be permitted to contest
*261
the extent of the plaintiff's disability and, therefore, that the motion to preclude should be denied.
Id.
The commissioner granted the motion to preclude the defendant from contesting both liability and the extent of disability because, although the defendant could not have commenced payment within twenty-eight days, it could have filed a form 43 during that period.
Id.
The board upheld the commissioner's decision. Id., at 267,
76 A.3d 657
.
On appeal to this court, the defendant claimed that the board improperly affirmed the decision of the commissioner.
Id.
It argued that it could not have complied with § 31-294c (b) to contest its liability because no medical bills had been generated within the twenty-eight statutory time period.
Id.
This court concluded that "it was not reasonably practical for the board to require the defendant to have complied with § 31-294c (b) ...."
Id.
We reasoned that the defendant could not have commenced payment of medical bills because
*636
no bills had been submitted for payment, and the defendant could not be required to file a form 43 within twenty-eight days of the plaintiff's claim because the defendant was not contesting liability; it was contesting only the extent of disability. Id., at 271,
76 A.3d 657
.
In
Dubrosky
, this court explained that there is an important distinction between an employer who is contesting liability and one who solely is contesting the extent of the employee's disability: "This distinction is not a superficial one, as an employer who is contesting liability is distinguishable from one who solely contests the extent of the disability. For example, in
Adzima
v.
UAC/Norden Division
,
177 Conn. 107
, 113,
411 A.2d 924
(1979), our Supreme Court recognized the difference between an employer contesting the extent of the employee's disability instead of its liability: The statute clearly speaks to a threshold failure on the employer's part to contest liability: to claim, for example, that the injury did not arise out of and in the course of employment ... that the injury fell within an exception to the coverage provided by [workers'] compensation ... or that the plaintiff was not an employee of the defendant, but an independent contractor .... See id., at 114,
411 A.2d 924
(no question that [employee's] injury was a compensable injury within the terms of the [workers'] compensation statute, i.e., that he had a right to receive compensation; the only contest concerned the extent of his lower back disability)." (Internal quotation marks omitted.)
Dubrosky
v.
Boehringer Ingelheim Corp.
, supra,
145 Conn. App. at 271-72
,
76 A.3d 657
; see also
Adzima
v.
UAC/Norden Division
, supra, at 113-14,
411 A.2d 924
(conclusive presumption does not bar employer, who has accepted liability and paid benefits on claim, from contesting extent of disability).
This court, in
Dubrosky
, then distinguished how the defendant in that case had been placed in a situation that the act had not contemplated: "The circumstances of this case, however, place the defendant squarely within a situation that the statutory scheme fails to
*637
contemplate, namely, where an employee files a form 30C claim for which
the employer does not contest liability
but fails to generate medical bills within twenty-eight days for the employer to commence payment. To require strict compliance in a case such as this creates an incentive for claimants to deliberately delay seeking medical treatment until the very end of the twenty-eight day period such that the employer cannot file a timely form 43 to avoid being precluded from contesting the extent of the claimant's disability because no medical bills are generated sufficiently within the statutory time period to allow the employer to commence payment ....
*262
"Thus, where notice, by filing a form 43 or commencing medical payments is impossible to provide in a timely manner, the failure to comply strictly with § 31-294c (b) will not preclude the employer from contesting
the extent of the employee's disability
.... Finally, we note the limited applicability of this excusing of strict compliance because in the vast majority of workers' compensation cases it will be possible for an employer either to file a truthful form 43 because it is actually contesting liability or to pay medical bills generated by the claimant within twenty-eight days. As
neither option
was available to the defendant under the circumstances of this case, it should not be precluded from
contesting the extent of the plaintiff's disability
when it filed its form 43 [seeking to contest only the extent of disability] within one year from the date of the injury." (Citations omitted; emphasis added; internal quotation marks omitted.)
Dubrosky
v.
Boehringer Ingelheim Corp.
, supra,
145 Conn. App. at 273-75
,
76 A.3d 657
.
The
Dubrosky
case is similar to the present case only insofar as the defendant in
Dubrosky
did not file a form 43 within twenty-eight days of the plaintiff's claim, and it was unable to commence payment within twenty-eight days because no medical bills had been submitted during that time and the plaintiff continued to work.
*638
See
id.
The defendant in
Dubrosky
, however, began paying medical bills upon receipt, and it then filed a form 43 to contest the extent of the plaintiff's disability. See id., at 265,
76 A.3d 657
. This court held that, under such circumstances, when a defendant employer does not challenge the claim of a work related injury, but challenges only the extent of the plaintiff's disability, strict compliance with the twenty-eight day statutory timeframe to begin payment of benefits will be excused when it is impossible for the plaintiff to comply. Id., at 273-75,
76 A.3d 657
. In
Dubrosky
, the defendant complied with the statute insofar as it was able, by commencing payment of medical bills when they were received and then filing a form 43 to challenge the extent of the plaintiff's disability. Although the defendant may have been precluded from challenging that the plaintiff's claim was work related, it was not precluded from challenging the extent of the plaintiff's disability because it began payments as soon as it could and it then filed a form to contest the extent of the plaintiff's disability. Consequently, the "safe harbor" discussed in
Dubrosky
applies only when the employer is contesting the extent of the employee's injury, and does not apply to an employer who is contesting liability.
In the present case, although the defendant could not commence payment within the twenty-eight day statutory time period because the plaintiff's bills were submitted several years later, it certainly could have filed its form 43 contesting liability within twenty-eight days of when it received the plaintiff's form 30C. In fact, although the defendant did not timely file its form 43 with the commission, it did serve the plaintiff with a copy of it within the statutorily prescribed time. In that form 43, which was untimely transmitted by facsimile to the commission, the defendant specifically alleged that the plaintiff's injuries "did not arise out of or in the course of her employment at [the defendant] and cannot be causally traced to such employment in accordance with [§] 31-275." Because the defendant was
*639
not seeking solely to contest the extent of the plaintiff's disability, but, rather, was contesting its liability for the plaintiff's claim, i.e., contesting that her repetitive trauma injuries were work related, it was not impossible for the defendant to file a form 43 disclaiming its liability within the statutory twenty-eight
*263
day timeframe. Accordingly,
Dubrosky
is not only distinguishable from the present case, but it actually reinforces the requirement that an employer who is contesting liability must strictly comply with the filing requirements of § 31-294c (b).
Because the defendant failed to file a form 43 to contest its liability for the plaintiff's work related repetitive trauma claim within twenty-eight days of the plaintiff's filing of her claim, we conclude that the plaintiff's motion to preclude the defendant from
contesting liability
should have been granted.
The decision of the Compensation Review Board is reversed and the case is remanded to the board with direction to reverse the decision of the commissioner denying the plaintiff's motion to preclude and to remand the case to the commissioner for further proceedings according to law.
In this opinion the other judges concurred.