I don't think an excuse has to be false to be funny.
I was watching a different match at the time, but during the World Straight Pool Championships (1982, I think), I overheard a player tell somebody "my bowtie cost me the match." It seemed a bit riduiculous, so I did some investigating. As it turns out, the player was at 147 and had to make three routine shots off a wide open table to win. Unfortunately, as he prepared to cue for his next shot, his clip-on bowtie (tuxedos were mandatory back then) fell off and landed on the cue ball for a foul (all ball fouls were in effect), after which his opponent ran out the match.
"My bowtie cost me the match." A lame excuse if there ever was one, but remarkably, true on this occasion.