I think discretion might have been a good thing here. Chances are, the coach was so sure of himself because his team had been called for this violation (or at least he thought they had) before by a ref he trusted.
My partner in the AAU games today told me he'd had a partner call a violation for a "double tap" against a jumper. The scarier part is, the ball had been tapped by both jumpers at once, hit the floor, and then one jumper tapped it off the floor to a teammate. Whistle, violation, throwin.
My partner asked me about it because it didn't seem right to him.