Supposedly from the guy he punched:

so here the story. some guy throws their wallet AT kudi… (his wallet, i don’t know why) being in the front, everyone reached out when he was like, “oh, who wants this?” of course everyone in the front is going to be “yeah its mine.” so i caught it and when he was walking away, i believe he jokingly said “if thats not yours, i’ma come get you”. a couple seconds later i felt bad so i tossed it on stage(clearly not throwing it at him but? just tossing it). this is what i dont get but he comes down, over the barricade and punched me. the people beside me were fucking awesome. lol the fans were actually holding him back. then the bouncer came and the show ended.? i still have my wallet.

I expect this from Wacka Flocka but not Kid Cudi lol.