Something very similar to this happened to me on Monday night, actually. Assistant coach stayed seated, but was hollering about illegal screens a couple straight times down the floor. "They're doing it EVERY TIME! EVERY TIME! MOVING SCREEN! CALL IT!" What did I do?
I showed the assistant coach my palm. "No more."
Next dead ball, I told the head coach that, while I would listen to her, I couldn't have her assistant barking at me all night.
That ended that--no more sounds from any coach all night. It helped that my partner and I made absolutely no errors
. I will therefore stick with that technique for hushing up assistants.
That said, if any assistant is on the floor and yelling, I'm giving a T.