one of my buddies has a saying, "when in doubt, run it out" and definitely has on occasion but luckily has come out on the safe side. I have some weird fascination with close calls, probably everyone who's climbed long enough has gotten that feeling of, oh shit why am I doing this when you turn into total self preservation mode, when you come out the other side successfully it is a feeling like nothing else.
The real "close calls" I've had have been fear free- I'll be falling almost in a bubble not really comprehending everything thats happening, sort of just floating downwards. The best thing close calls have done for me is given me a better understanding of just how far I can push it- thats part of what climbing gives me, getting so close to the void and then snapping back into the safe space. The best definition of "flow" I ever heard used climbing as the example, a high amount of risk coupled with a high level of control.