[Kansas Ref]

We had a JV girls game, defender pushes in the back forcefully the player that is shooting a driving layup. Player misses the shot and crashes face down to the floor, the ref covering the play rushes in and says very audibly "flagrant foul" while raising his index finger into the air (seemed even louder bcuz gym was sparsely populated). He told us at halftime that it was the signal for a "flagrant foul". He was the senior crew member somewhere 20+ years it is widely known.
Is that proper sign or has he been influenced by watching too much tv?