From what I understand he wasn’t actively doing hard drugs, but had earlier in his life. Maybe that’s not correct. I’m not sure. But if he was addicted and she or anyone else was further encouraging or indulging his addiction, well, that’s abusive by any definition I hold.
I’m not sure about his personal relationships, and don’t care much besides leaving an internet comment, but why are you so quick to dismiss that he may have experienced being manipulated or taken advantage of?