Didn't have my calculator handy.;)

slippery slope
 

They play to the whistle, not the shot clock horn, which should be different from the quarter ending buzzer. The end of a period buzzer means nothing that happens afterwards counts. The shot clock may, and sometimes does, go off with the ball is still legally in play.

I cannot see giving a team a Mulligan for playing to the shot clock rather than the whistle.

I think it depends on when the horn goes off and how the teams (plural) react.

As described in the OP, the officials are going to stop play to reset the clock anyway.

Yep...We pre-game...whistle at the end of a quarter/half by THE official with last shot responsibility (seems like to often we get 2 whistles at the end of a quarter/half in a 3-man crew)

Also, whistle for every sub.

Sorry to keep the hijack going 1 tick longer, but I finally had time to look this up: There is no mention of a whistle in IAABO's Substitution Procedures and Guidelines, which explains why BillyMac and I, living in IAABO states as we do, don't practice this.

But I have no issue with it.