I don't believe in regrets and hand-wringing. I am self-aware enough to know that I made an informed choice and I saw most of the red flags in my current lab when I interviewed. I didn't expect them all to be true, but that is a different matter.
I interviewed over one long weekend, in one area. I did restrict myself geographically for personal reasons, and that geographical restriction is turning out to be the best past of this experience. Anyway, over that weekend, I interviewed with five PIs and three labs. One experience was excellent, saw some potential problems, figured awareness was half the battle. One experience was really good, but I would have ended up being the senior person in the lab and the PI wasn't even directly offering me the job anyway. The other three were washouts. I was already pretty fed up with the process, because I had a few pre-screening rejections based on the tight funds at the time and my average but not sexy CV. So I didn't send out more applications and accepted offer from said excellent interview experience.
Red flags and all. And everything I thought might possibly go wrong did. Everything possible. Which really sucks, but I thought they were all possible. I also think that every lab has its, shall we say, quirks. I didn't expect the personality of the PI and the community of the lab to be this negative. I have some wonderful colleagues, so it makes it easier, but otherwise, not good. And the general research environment is not conducive to one's greater professional development.
So, I made an informed decision and took a chance, it didn't pan out. I'm dealing. But, in restrospect I should have interviewed more, seen more places, other labs, other dynamics and then decided.