The first year I ever reffed (after my training by Dr. Naismith) I was working a 6th grade girls rec game. The other ref was in his first year also and was a teenager, so he kind of let me be the ref "in charge". A1 went to the line for two shots. She violated on the first and I ruled she also lost the second shot because of the violation. The coach, who happened to be not only her father, but also an ex-NBA player, didn't really argue but "teased" me a little about the call a few times during the rest of the game. He always had a big smile and a friendly chuckle when he did it and his comments were somewhat friendly and funny, so I just returned his smile and didn't create an issue with him.
Oh yeah, I remember one time I made a mistake of not hitting a coach over the head with a frying pan when he mouthed off and wouldn't sit down. I've never made that mistake again.