Moshkito
Hi,
The only thing that is weird, to me, is that the majority of the audience, has absolutely no idea what he is talking about, and that they could continue playing around with the piece, and we might even think that they were working on something new.
From a rehearsal perspective the thing here to do is NOT to stop, which Tony didn't, because that is usually the dead giveaway.
No worries, KC will be ready next time, and I bet they will intentionally mess up on this same spot, because they found something to fool around with ... fun times!
There is a guitar player who I used to play with long time ago -- he would throw his hands the air and shake his head when he made a mistake - It was an advertisement for CRAP I just messed up -- when really no one would have noticed until he spotlighted it in (shakes head)