Gary had been getting on Meat's nerves back over the past few tasks. I believe he even said at one point that if Gary wasn't kept away from him he would probably lose it at some point. This imagined theft of the paint supplies was what put him at the breaking point. He was just looking for an excuse to explode, probably knew it would happen and couldn't do a thing to stop himself.

Back to Richard Hatch...after Jose Canseco left to be with his dying father, Richard hinted that this may have been a setup for a planned exit. Very nasty & coldhearted. All the more reason he deserved to go.