Years ago the wife and I were caught in the middle of a similar situation as yours. It sounds like your friend has a better handle on things than what our relative ended up having.
There have been a few course-altering lessons in my life. Luckily I do believe I learned from them. Yeah, there was one that I did not learn from that kicked me in the ass good for a long time. But isn't that how it usually goes with those types of lessons?
It's never an overly pleasant situation even for the one who went out and did the deed. There's often underlying or extenuating circumstances around it though which makes it problematic for those on the outside to get a good handle on the situation. I guess some understanding is required and support in the hope both parties can find the best collective resolution and way forward.
I agree with your last bit, often the ass-kicking situations bring the greatest lessons and benefits down the track although it's pretty hard to see it that way when in the moment, or has been for me at least.
I appreciate your valid and open response.