Affiliate Marketing Secrets

It was on the sidewalk on a college campus, so I didn’t want to just leave it for someone else to find, and I know the bank it was affiliated with has a pretty ridiculous replacement fee, so I stopped at the bank on my way home and expected to just leave it with the teller and walk out (Which is what I once saw someone do at my bank.) As I began to walk away, however, the manager stopped me and asked to see my license “so I wouldn’t have to stay there.” They copied down my information and let me go after that, but now I’M suspicious. I did some facebook snooping and there is only one person with the name that was on the card, and she does attend my school, so it’s highly unlikely that the card ever wound up in the wrong hands, but can she still claim that unauthorized purchases were made? Does the bank have to report this to the police for some stupid reason?
I doubt anything will come of this, but I just want to know if I should be concerned/how to go about covering my own butt.