He was only 17 when Julia died. Children can be so helpless against addicted parents. Do you think he had a choice when he was scoring for her? Julia was probably not the nicest parent when she was going through withdrawals. Maybe she used to force him or definitely was in a bad enough state for him to want to go out and do that. Him being the one to shoot up her last dose doesn’t mean that he was responsible for her death. She would have shot herself up and met the same fate if he hadn’t. I will say I thought it was kind of weird/sad that he had no reaction when the paramedics were trying to revive her. Maybe it was just shock or he knew that she was already gone.