Thanks. I went back and checked that after I replied. I remembered that was the terminology used by an instructor in a clinic I attended. Don't know where he got the term. The rulebook or casebook doesn't say prone!

Jim Paronto's interp (NCAA Secretary rules-Editor):

Obstruction Rule 2, Sec. 50, AR 4

applies not only to intentionally kicked at (similar to video) but also deflected ball, F1 had his chance to make a play on the ball, and must avoid the runner even if in the act of picking up the ball