I may have posted about this before, but I was at a game a few years ago when the clock/TV thing came into play. Missouri State was playing at St. Louis University in 2006. MSU was up 50-49 and SLU had the last possession. They took a shot with a couple seconds left, followed by a tip-in at the buzzer. The officials went to the monitor and ended up counting the basket. A day or two later, it came out that the TV broadcast that they used to watch the replays was off by 3/10 of a second, so the clock on the screen showed .3 on the clock when the ball was tipped. If you watch the video of it below, you can actually pause it at a certain frame and hear the horn start to go off and the ball isn't even touching the shooter's hand yet on the tip-in.
SLU vs Missouri State Basketball - YouTube