In one of the "flop" reels the defender grabbed him with both arms and pulled him to the ground. That is not flopping.
The "flop" is when someone touches his chest and he dramatically throws both arms in the air to draw attention to the fact he is apparently dying. If the refs are annoyed by it, then they should send him off to be checked in the concussion protocol, because "wow thst hit really floored you... you went limp!" As long as they are consistent with other QBs... one rule for everyone.