I asked a question, which failed to get posted because Stack Overflow went down, and then I re-asked the question, and got captcha'd because of that.
I shouldn't be captcha'd because the Stack Exchange software made a mistake on their end.
There are many variables that go into whether we show a CAPTCHA or not. But that aside, I don't see how our code would be able to tell that there was an unplanned outage, or an error, or anything wonky on a previous request... and even if it could, how we could differentiate anything that's our fault from any failure on your end.
In short, I'm sorry you had to spend some time filling out a CAPTCHA, but this isn't really feasible to implement.