The information they would need to verify his story. There are people here friends with him on facebook. A phone call to the security company and a quick ten second conversation with the guy who gave him the tickets would clear a lot of this up.
Of course I'd still be pissed if I gave him money for the dog. That $200-300 he spent on the trip could've easily gone to the dog's fund, and there's no excuse for not being upfront with people in the first place.