I wonder why he thinks it is me. Is this some sort of guilt?
It is not guilt. He thinks its you because you are the closest thing around him, and he knows you the best. He is in DENIAL and it can't be him! So who should it be if it is not him, you are next in line. Detaching sometimes works because what happens when you are not around anymore, then he may have no choice but to look in the mirror at himself.