Player starting to fall in anticipation of charge

[drofficial]

In the OP I was not intending to describe a player faking a foul. It's a player who knows he is going to get run over and so starts to lean fall back. The problem, for the official, is that this lessens the contact. So the question then becomes was there enough contact to gain an advantage, or did the defender's starting to fall mean that no advantage was gained?

I had this play last night and had a no-call, but then the offensive player basically fell on top of the defender on the floor, so we have a "crash" under the basket and a no-call looks suspect...