In a game this year we had a D end grab the QB by the facemask. QB fumbled the ball and it was picked up by the D so I was running with them, but the R stayed with the QB and described it as this:
After the initial hit, the B player then set his feet with his arm extended (while holding the facemask) and pulled the QB around in a huge arch before slamming him almost head first to the ground.
This action was used to determine that the B player had removed himself from the competition.