Johnny and Lisa are in a scene. It's a dramatic scene early on in what could be a longer story. Johnny is relating a traumatic incident that seems to define his character's current world view. He explains that he witnessed a horrific mob killing. It's clear he was traumatised by it. He begins describing in detail the scene and Kris and Sly start re-enacting it in split screen. However, whist doing what Johnny is saying, they do it in a very comedic way. It's funny, but somehow the story is flat afterwards.
Kris and Sly say they chose to do the scene lightly because the other scene was so heavy. It's true the story had been heavy so far, especially that scene with Johnny and Lisa. And it's also true some levity will help the story and keep people involved. But that point was not the time for it. The next scene might well have been ripe old time for some comedy, but there and then, it was not what the story called for.
I'm not saying the comedy "hit" scene wasn't funny. It was hilarious. But its humour came in part from it being at odds with what was set up. Funny is all well and good, but it should not be at the expense of the story and characters. Not if you hope to sustain a story.
In this case the "at odds" really fell into blocking territory. In a short, self-contained scene, this wouldn't matter so much, but here what we were supposed to be seeing was what made Johnny's character the way he was. It has to be as traumatic as he tells it. If it isn't, it means that Johnny is traumatised by something we know to be comic. All the sympathy we would have had for the character evaporates and our interest in the story with it.
Obviously, we can have stories where the truth is at odds with what characters say, but this is very hard to do improvisationally (not least because it is not the obvious thing and it involves an idea from outside the scene). In this case it certainly was not what had been set up by Johhny and Lisa's scene. The "flashback" we were seeing, because it coincided with Johnny's description, was clearly from Johnny's character's point of view. Sure, maybe the killing was
comedic to those who did it, but not in Johnny's character's mind. The killing from his point of view was brutal and traumatic. In a movie, even a comic movie, that’s what we'd see.
I got them to do the scene again, this time Kris coldly shot Sly in the face. It was chilling and everyone felt uncomfortable, but that was what the story needed and our sympathy as an audience was now firmly with Johnny. So much so that, at the end, were Johnny's character to get some form of closure (by making Kris repent, or having him arrested or (most often in movies) by shooting Kris himself) we are so frigging pleased for him in a way we would never have been if his issues had all come from something that was like a clown shooting a mime in a school of overacting.