I'm glad to hear your method worked out too, but here's how I handled a similar situation.

Last night boys sophmore tourney early in the 1st quarter, Team A player voices displeasure about any foul/violation call against his team. I speak with him about it & address his teams captain on the issue as well. Captain says he'll "take care of it" for me.

2nd quarter the block call goes against said player, he jumps up yipping again... Whack
On his way to the bench & before the sub is beckoned the player flails his arms at me, as if to say "I dont give a phuck"... Whack

Coach he's done.
20 seconds please.
Have a seat young man.

The player chased me down to apologize post-game as his coach watched from a distance.
I really hope they make it to the Championship game tommorow, so I can interact with the kid again, he's a very talented player... maybe it was a good lesson to learn now rather than later.

That's how I handled my situation rather than talking to the coach about it. After all what does coach know, he wanted shots on offensive fouls & 3 seconds called before the ball was inbounded.

Not that I'm keeping track or anything but 3 Ts & 1 ejection on the season so far. The common factor is that the Ts were given on lower level contests


NOTE: At halftime we wait at midcourt until both teams & their coaches have left the vicinity of the gym.