It’s not a mistake on an improv stage as long as you recognize what happened and in some way react to it, right? Your pure reaction to someone walking through an improv table that you just took a minute to set up, is justification enough that they walk through the table. You don’t need to call somebody out and say “You just walked through my table!” You know that’s going to alienate them and alienate the audience likely, and then you’re going to spend the rest of the scene trying to dig yourself out of that callout. As opposed to just go over, pick up the table, set it up again, patiently, diligently, and then when somebody else walks over, don’t even mention a word, just go pick it up again and do the same thing. That’s going to create laughter from the audience because you’re respecting the environment and showing that there are no mistakes. That wasn’t a mistake they walked through the table, that’s a gift that’s an opportunity.
Bill Kullhan on accepting mistakes from Improv Nerd E225.