Assuming that the candidate was in the wrong here, and the interviewer wanted work anecdotes, why didn't the interviewer guide them to the right topics? If they didn't guide them to the right topic, your assumption that they wanted work examples may be flawed.
a) The potential employer vastly overstepped commonly accepted boundaries.
b) It was totally implied that the questions were to be answered in the context of work. "What was the hardest challenge you had to overcome?" in that context relates to e.g. debugging a hard concurrency problem, not your divorce.
What stood out to me is that whatever interpretation is the correct one, the candidate was willing to give (apparently) deeply personal answers. That's just something to adjust for in upcoming interviews, we live and learn.
What would be the point of conducting an entire hour+ long interview where the candidate is only giving you irrelevant answers and you make no attempt to get them on track?
It is common for people to ask a personal sounding question but expecting an impersonal answer.
OP took it at face value. I can relate.
Alternatively, the interviewer was a psychopath. (I can also relate!)
Probably only thing I would’ve done differently would have been to limit first call to 30 minutes to save me time when someone is obviously a bad fit.