Unfortunately, the NBA is all about acting. If Collins stayed on the ground, after Embiid backed him down, and acted like he was hurt, then the referees may have reviewed the play as a hostile act and assessed a flagrant 1.
In regards to game 7, there was a play towards the end of the game when Huerter attempted a 3 and Thybulle tried to block the shot from behind. Instead Thybulle pretty much elbowed Huerter in the head so hard, Huerter’s head may have hit his shoulder. I thought any contact to the head was essentially an automatic review for a hostile act. There was no review. I immediately thought to myself, if Huerter had stayed on the ground and acted dazed, the referees would have been forced to go to replay.