Falling down with the ball

[IREFU2]

ART. 5 . . . A player holding the ball:

a. May not touch the floor with a knee or any other part of the body other than hand or foot.

I was talking about this part when he/she lays back and the "any other part of the body" touches the floor. Maybe I am looking to far into it. I have seen this called every time it has happened. I am not trying to cause a debat or arguement, just want to get it right.