An extension of time must be granted if the motion and affidavits filed by the movant set forth facts which, if true, would negate intentional or consciously indifferent conduct. See Director, State Employees Workers' Compensation Div. v. Evans, 889 S.W.2d 266, 268 (Tex. 1994). Some excuse, but not necessarily a good excuse, is enough to warrant an extension to file an expert report, as long as the act or omission causing the failure to file the report was in fact accidental. See Horsley-Layman v. Angeles, 968 S.W.2d 533, 536 (Tex. App.--Texarkana 1998, no pet.). The burden is on the party seeking relief to show some evidence of accident or mistake to demonstrate that he did not act intentionally or with conscious indifference. See Schorp v. Baptist Mem'l Health Sys, 5 S.W.3d at 732 (Tex. App.--San Antonio 1999, no pet.) It is then the defendant's burden to controvert the plaintiff's evidence of mistake, or else an issue of mistake exists and an extension of time must be granted. See id. In determining whether the claimant's failure was intentional or the result of conscious indifference, we look to the knowledge and acts of the party seeking relief. See Nguyen v. Kim, 3 S.W.3d at 151 (Tex. App.--Houston [14th Dist.] 1999, no pet.) An accident or mistake in this context is generally characterized by the claimant's inadequate knowledge of the facts or by an unexpected happening that precludes compliance. See Nguyen, 3 S.W.3d at 152. Conscious indifference, on the other hand, means failing to take some action that would seem indicated to a person of reasonable sensibilities under similar circumstances. See id. A motion for extension of time is necessarily implied when an appellant, acting in good faith, files a notice of appeal beyond the time allowed by Rule 26.1 but within the fifteen-day grace period provided by Rule 26.3 for filing a motion for extension of time. See Verburgt v. Dorner, 959 S.W.2d 615, 617 (Tex. 1997) (construing the predecessor to Rule 26). But "once the period for granting a motion for extension of time under Rule [26.3] has passed, a party can no longer invoke the appellate court's jurisdiction." Id.