Defender intentionally falls onto hands and knees...

[just another ref]

Originally Posted by Snaqwells

....... it's clearly a PC foul. I'm not sure the justification for not calling this.

This is a pretty common misconception, I think. Hopefully, it's mainly among only the spectators. Years ago, friends were critical of a PC call I had made against their son, and they had video of the game. Later, I saw the father and was told, "We watched the video, and that was a bad call. Nobody fell down or anything."