Found a wallet and... (Munich)

Hello everybody,

I just have a case I'd like to share with you to know what you think about it.

Yesterday I was at the Franz Ferdinand concert and after queuing up at the bar I saw a men's wallet left there. So I turned quickly to spot the guy who might have forgotten it there. Eventually, I got the guy's and gave it him. He just went away.
I felt so weird afterwards and even a bit guilty, maybe it wasn't his at all?

What would you have done instead?

A bit of background for better undesrtanding, it was the end of the show, my feet and ears soar and I was deadly tired.

Am curious to hear from you guys.

Thank you!