My wife was almost killed due to a botched surgery (for cancer). She felt bad for weeks afterward - and every time we returned, we were told she "just needed more time". So I finally admitted her to the ER where they declared she was in septic shock.

I inquired about suing (to some attorneys who specialize in this sort of thing) and was basically told that there was little chance of any recovery, and it would be a large burden on us to literally re-litigate the entire traumatic event. So we passed.