You're Driving Me Crazy

[Kansas Ref]

Signals: I frequently see refs exhibiting this hand signal in a "1 & 1 FT scenario", 1st FT try is missed and the ball does not contact the rim, but just bounces off the backboard and lands on floor--the T will pop his whistle, then point to the sky and swirl his index finger around in a circular motion.

My partner did this last night and I told him about it at our halftime locker room break. I asked him as politely and measured as I could (because I know that he chaffs at being corrected on things) I asked exactly like this: "hey, I was curious as to why you were using that finger swirl signal on that missed FT when you were in the Trail?" He replied, "this is the signal we all use for missed FT's, everyone does it, don't you?"
I replied: "the signal you are showing is for a basket interference; for a missed FT which does not hit the rim simply use the normal violation signal (open hand held up) and indicate that we are going the other way with ball now".
He replied: "are you sure about that?"
I did not have my NF books with me, so I could not shew him proof; but I did say "I bet you a pizza that it's true". He said "you're on". Looks like we don't ref together again until January. I realize it is prolly a habit he picked up from watching other refs or it could've been a signal that has since been deleted from the NF? At any rate, it's driving me crazy to see certified refs inappropriately exhibiting this signal.