I had a post about things I noticed regarding the night SG disappeared and just lost the whole thing! I hate that and I don't have time to redo the whole thing, but the short version:
The doctor issue really sets my radar off. First the CVS visit, if the pharmacy was open at the time of their visit I think it is likely that a prescription was part of the deal that night. They went to the party/date location very briefly and then went to CVS and then came right back. There prescriptions, like oxys for example, that cannot be called in. You have to have the written script from the doctor. If the CVS visit was for supplies, condom/lube/or the like they could have stopped on the way. It is possible the need for said item wasn't known until they got to the house, but the timing doesn't support that scenario easily.
The doctor calling the mom/sister in the days afterwards, the story about those calls changing, and the halfway house really stand out to me redflags. If the serial killer in this scenario is a *respected* member of society by day and preys on the prostitutes in my other life, well a noble venture like a halfway house would put me in contact with these women in a way I don't have to hide, that can be explained.... actually puts me in a trusted role with the women who might treat me with a bit more caution as a john. There are multiple girls that took unusual risks with their last call. Didn't take their phone, didn't take their normal safety precautions, that seemed to know or trust the person they were going to meet.
SG clearly was panicked and irrational at the end of the evening. Clearly she was in danger but the 20 minute 911 call was made from inside the john's house. For some reason I had it in my head that she made that call from her cell, while already in escape mode. Being in the house, not in escape mode, being able to stay on the phone that long.... I don't think she had been attacked, choked, etc at that point. I think being drugged, by her own accord or by someone elses hand, would definitely contribute to her not being able to communicate with the help she was close to so many times in that last hour. There is the 911 call that she was able to make and stay on so long with but not able to communicate in a way that would identify her location. She made it to the neighbor successfully, now had an open door, a witness, another call made to 911 but this time with a location but she fled what could have been safety back into danger.
I was expecting the COD to a combination of toxicology and a cardiac event. She was possibly drugged and had an extended period of extreme panic/shock culminating in the physical exertion of running for her life. So much time had passed before they found her though we will probably never know.