No I get where you are coming from. His is what my ex wife says. She says she will never understand and that’s why she cant ever forgive me. That’s her choice and she thinks going support groups wont help her as she will just judge etc.
I recommend if you are willing to support him go to support groups. There is also helplines you can phone.
Dont batter yourself for not finding out quicker. These are his actions and he needs to face them.