timing question

[Troward]

This happend in the Celtics game on Wed and I wondering how we would handle it in NFHS.

There was a violation (shot clock in this case) and the official blew his whistle and just after the whistle the horn sounded that the quarter had ended. The whistle and horn were close enough that I thought they could have just called it the end of the quarter but instead they put .6 seconds back on the clock and ran an inbounds play which resulted in a way off half court shot which they blew dead b/c there was not enough time to attempt a legal shot. The effort seemed like a waste, but I wouldn't want to seem lazy.

So the question is: if the horn sounds after the whistle is it logical to always assume there has to be some time left b/c the whistle should have stopped the clock?