[jamesdeane]

Bottom line:
It's the rule
Coaches & players know the rule

What's the rule?   If the refs are huddled up behind some cheerleaders and parents and a player dunks is it a foul ? Where do the refs have to be positioned in order for technicals to be called and the coach ejected and suspended for three additional games?  Are coaches expected to go looking for the refs in every nook and cranny  of the gym? Why can't refs blow their whistles to announce their arrival?  Remember, dunking as allowed during warmups. When does it become a foul?  The rule should be changed to either no dunking at all or dunking allowed at all times .

The rule is there is no dunking during warmups.   This is the rule it has nothing to do with when officials come on to the floor.  So the rule is simply ignored until officials coming on the floor, sort of like speeding 99% of us do it until we see and officer.

This is the simplest and best explanation.