FT Shooter wearing necklace

[colled4]

This happened in a rec game I was watching Saturday - been thinking about it ever since. Early in the game A1 is fouled and goes to the line. R notices that A1 is wearing a necklace (it was under a t-shirt and is now poking out) and sends him to the bench to remove and has Coach A replace the player. Coach B goes balistic becuase A6 is a much better FT shooter.

Now if I am doing a rec game, I probably would have the kid take of the necklace and give it to me to give to the coach the next time I went by him, or just have him hand it to the coach. But coach A is someone I talk rules with a lot and I know he is going to ask me about it tomorrow when I see him.

So - was this by the book? Having a hard time finding relevant rules.