CCTV shows you were in the general area of the crime, but your shady friend says you were hanging out with him at the exact time the robbery happened, and the guy who says he saw you do the robbery is also kinda shady. I think it’d be reasonable for a juror to think you probably did it (because your friend is untrustworthy and has obvious incentives to lie) but didn’t do it beyond a reasonable doubt (because the witness just isn’t credible enough).