From McClain v. Norfolk So. Rwy. Co., 2009 U.S. Dist. LEXIS 22474 (N.D. Ohio Mar. 16, 2009):

Through counsel, plaintiff volunteered during his deposition that he took pictures of the catwalk. Now he can't retrieve them from his cell phone. He doesn't know what happened.

According to the plaintiff's opposition to defendant's motion to exclude all testimony about the condition of the catwalk as plaintiff observed it, the railroad has its own pictures of the same area.

There is no reason to fear or conclude that plaintiff deliberately destroyed probative evidence. In any event, whether defendant has its own pictures or not, the eyewitness observations by plaintiff and others will suffice to give the jury a mental picture of what the scene looked like.

To grant defendant's motion would mean that whenever photo- or video-graphic evidence, once acquired somehow became unavailable, a court, regardless of the quality or probative value of the missing images or fault, or lack thereof, would have to disallow even first-hand testimony by percipient human observers who saw what was there.

That's not the law, as the Sixth Circuit, sitting en banc, recently made clear in Adkins v. Wolever, 554 F.3d 650, 652-653 (6th Cir. 2009):

failures to produce relevant evidence fall "along a continuum of fault-ranging from innocence through the degrees of negligence to intentionality," the severity of a sanction may, depending on the of the case, correspond to the party's fault. Thus, a district court could impose many different kinds of sanctions for spoliated evidence, including dismissing a case, granting summary judgment, or instructing a jury that it may infer a fact based on lost or destroyed evidence.

(Citations omitted).

The fact that plaintiff can't explain what happened does not, without more, raise in this case an inference of fault, much less deliberate misconduct. I find no reason to impose any sanction whatsoever simply because plaintiff no longer has what once he had.

[Footnote 1] I leave for later resolution any dispute as to whether the jury will learn that plaintiff took the pictures he no longer can retrieve.