I think I shared this earlier, but here's mine:
It's my first year this year: JHB, I'm administering a throw-in after a timeout. Defender breaks the plane of the OOB line and whacks the thrower on the arm. I get my fist up and go to blow the whistle and....pthuh. No sound except my whistle banging against my shirt. My partner blew his whistle for it, chuckling down the court as he reported it. Coach asked why he was making that (obvious) call from so far away; you could her the slap from a mile away.