My two cents...
Whether Sabonis intentionally grabbed at Draymond's leg or not is only something that we, as fans, can speculate. But, the truth of the matter is that Sabonis went down hard, and probably got the wind knocked out of him enough to not completely be fully within the moment. He was probably feeling around trying to make sure he still has the presence of mind to understand that he is down on a basketball court, and can feel his way around - I totally get that.
From Draymond's standpoint, I can also see where he might have been a little annoyed at Domas grabbing his leg. If I were Draymond, and I wasn't fully aware of the current situation (i.e. Domas not really knowing where he really is right now), I, too, would have "assumed" my leg was just being grabbed at for the sake of either taking me down, or preventing me from advancing back up the court.
Regardless of what Sabonis was thinking at that time, and regardless of what Draymond was thinking at that time, the bottom line is that Draymond had no business to stomp on Domas while Domas was down. If he had any other reaction (i.e. get up in someone's face for a minor confrontation), I would have been fine with it, because it is a part of the game. But don't go around stomping on a fallen opponent just to make your damn point.
For those pro-Warrior fans who are defending Draymond, I just hope you're defending Draymond because of the sheer fact that his leg was grabbed, and are defending his right to simply react. Just don't be defending that punk for reacting by stomping on another human. If you simply feel that he had a right to react, I hear you, and I agree with you. But if your argument spills into you thinking he had a right to react the way he did, you need a lesson as much as the next near-sided idiot in line.