I played a rebuy tournament for the first time yesterday on PP. It were only a $1 rebuy and i noticed that one of the players at my table was doing the following almost every hand.

PF: Villain puts in a 3 or 4XBB raise. As the blinds were low he was almost always getting at least 2 callers

Flop: Regardless of the cards, villain pushes AI.

Usually everyone would fold, then after the pot had headed his way, he suddenly had another 3000 chips on top of those in the pot. He was pushing AI and then opting to rebuy when all his chips were in the middle, and the software was letting him get away with it. So after about 30 mins he had a stack that was 8 times the starting amount. When i called him up on it, he replied "That's how you're supposed to play rebuys". Surely to god this isn't legal?