From Joseph Goodman of the Miami Herald:
Upset with himself over missing a shot, Beasley started punching himself in the head while running back on defense. He punched himself so hard that he needed treatment after the game from the Heat's trainer. Steel compresses (like the ones cut doctors use in boxing) were applied to Beasley's brow in the locker room.
It's funny, of course, but it's also a little sad. Beasley has all the physical talent in the world -- folks had actual arguments about whether he deserved to go No. 1 over Derrick Rose back in 2008 -- but he never managed to pull it all together. It's obviously mental, right?
Oddly enough, Beasley actually had a solid game: nine points in nine minutes on 3-5 shooting, adding a couple of boards, an assist and a block. He failed as a franchise cornerstone and seemed like he tried to do too much the last few years on some bad teams. If he can rein in the emotions, perhaps he can reinvent himself as a role player on a contender.
Update: If this is actually the video, I'm kind of shocked it required treatment after the game -- it doesn't look that hard to me: