I don't know if you saw the message, but if you factor in savestates as well, and the fact that his flash cart can do 4 saves on the same game, you can see how he could get multiple sinjohs on the same game.
Oh, and just to explain, he got pissed because he RNG'd these things then gave them away to whoever wants them. Dunno if it's ever happened to you that you get slapped in the face for being nice to people, but that's kinda what happens when people call them hacks. I'd be pissed too.