well, as John pointed out, the question really was 'how should the belayer respond?' to a potentially dangerous situation, so to follow your point, the issue is one of why the belayer and leader seem to have perceived the situation differently.
I would contend that we've pretty much ALL done things we're not proud about after the fact. And got away with them. Last week I led Insuhlation with the intent of climbing calmly through the crux, placing gear and not running it out above that keyhole as I've done before. Instead I got to the intermediate edge, started to gas, went into "Oh no I'm doing a SethG (sorry bro:-)" and jiggered in a very shitty piece. Yeah I knew the jugs were above but sometimes you just don't got it. Hung on a couple of lobes and then fired in another piece immediately. But I totally dodged that nasty ride. It was really dumb and I regretted it. I was almost exactly on the other end of John's situation, except that I had the presence of mind to fire in a backup and finished the lead.
In
Deep Survival, Gonzales contends that often we confuse 'getting way with it' with experience. Not sure how much I buy that argument, but there seem to be a lot of people being rather 'holier than thou' about this.
Dodging something bad is central to climbing. Thats why the ropes are there. I think the calm discussion afterwards once you've both gotten away with it and everyone is safe is the ticket. Everyone is teachable. I appreciate people pointing out possible imperfections in my gear or other improvements. They will save my life one day.