Duke/Clemson timing error

[tmp44]

For those of you that have seen the play/saw the game:

I understand that more than .6 seconds elapsed -- that seems to be clear. But, is there anyway that the only definite knowledge that the officials had was .6 seconds? Regardless of everyone guestimating that it took 2.5 seconds to get the shot off, what actions, from what you guys saw, would justify them putting 4.4 back up?

Is it possible that, since there was no definite knowledge, it could have been .3 + .3, that is, reaction time to start, plus reaction time to stop, that led them to take .6 off?