I have don't disagree with the validity of any of the comments nor the documentary except a key player in this story is missing. That is Sid's mother. Other docs have brought up the fact that she was there that night. I don't know if this is out of respect for her, respect for Sid or some other reason. But Nancy's relationship with her was said to be very toxic. It was rumored that Mum gave Sid that last injection after being told by friends not to because of the strength of the heroin. It just surprised me that this film made no mention of her & her influence in the final chapters of both Nancy & Sid's life.
Unfortunately I can't list the docs that I have seen that portray this side, but they're out there if you're willing to invest the time.