Ask to see a Driver's License, If he is one of the guys we know, or knows the people we run with he should not be to upset, But if he won't the ask him not to come along because you don't want to be with someone that doesn;t have thier endorsement and if they crash u need to know who they are.
Whent the wallet comes out he will have a badge next to his DL, it is how they carry unless they are truley UC, but a true UC wouldn't hessitate and would spend much longer getting to know who is whom.
No one on these rides should be offended if asked to prove who they actually are. And if it ends up being a mistake then they guy wil know that the rest of us are just trying to cover our asses-EZ