"Very ill" is doing some heavy lifting there. He's on a psych ward because he can't handle the truth about his abuse coming out.
That is the very definition of a self-inflicted harm. He wouldn't feel shame and fear and abandonment if he hadn't been an abusive arse to hundreds of people, would he?
I pity his 12 year old. I hope his mum is a resilient and dependable woman who can help him through this. It's not his fault that his father is a sex pest.