Sumsky. This may not be deliberate, planned or even conscious. He may compartmentalize. Not want to or be able to think about what happened. He cannot face it.
You are the one who is ascribing motive to behavior that may not be motivated as much as defensive. Him protecting him against awareness of him.
I am in no way defending him. Or advocating for a diagnosis of one thing over another. I am saying YOU will be better served if you do not fill in the missing blanks with INTENT on his part, PLANNING on his part, DELIBERATION on his part. *Although these have not been ruled out, yet. This child is sick. He has fallen apart. He is trying to recoup. I feel for him. He must feel he is on the brink of losing everything. I really, really feel for his Dad and you, both of you.