>>936854080Think of it this way. If you're losing an argument, but then make a witty joke to change the subject, if you make the audience laugh, they'll think you won. If your opponent tries to bring everyone back on point, he'll look like a sore loser desperately trying to regain control, even if he's right and makes complete sense.
This is why I always say joking means you lost. I've never used it in person before though, but I have a hunch a crowd would just boo and say "that's not funny."