It wasn't me, but I nominate the
blarvel.
I think we've probably all called a violation on the wrong line once or twice in our careers, especially on the some of the 'multi-purpose' gyms with a main court, 2 side courts, a volleyball court (or two, or three), et al.
I have a hard time coming up with a specific "worst" call, but I do one specific instance my first year. I was the lead, post player on the block got absolutely mugged on a try attempt (could've probably considered a flagrant). I froze. Eventually, my brain said "THAT'S A FOUL! WHY DIDN'T SOMEONE CALL IT?"
About 3 seconds later I remembered that I was supposed to be the one calling it.