People can lack Responsibility

Alright, it takes a lot to piss me off, but this one customer I had to deal with yesterday didn't even have to try. I'll try to summarize this in as little words as possible.

The customer came into the store looking to make some trades, every single game he gave me was scratched beyond repair, but it was only when I reached his one PSP game that he actually had a comment. I attempted to remove the game, but realized that the casing was split, so I didn't bother, I explained that the game was already broken and the customer took back the game and removed the game from the case. Obviously, the game broke in his hand and the first thing that comes out of his mouth

"Why did YOU break my game?!"

Honestly, I didn't even take the game out of it's case, and he has the balls to say that I broke his game? I really hate being called out like that, take some responsibility for YOUR actions.