I've read thru all these posts and never wavered from my gut feeling. Prisma was slipped a roofie (Rohypnol), but after ex/current left, when she was alone, when she went to the restroom probably, closer to the end of her stay. Her actions after are textbook for after consumption. An inebriated state is suddenly demonstrated, the tab indicating how much she drank is vital, I imagine it's no more than a bartender would be comfortable serving, and those who spoke w her at the restaurant said she didn't sound intoxicated, this escalated to her being thrown out in a very short time. So she bats the hell out of there, you can see her exit, pissed and confused because of she feels like she's drugged, she's heading home and it's getting exponentially worse, and she thinks her ex/current slipped her something, she feels things unraveling and knows she will soon be unable to drive, so abruptly turns back to go to her exes/current apt. From their her confusion and disorientation are rapidly overcoming her and she starts making the confused calls, she goes from asking for her exes room number to not knowing where she even was. Prisma was a heavy drinker, unless that bartender served her 15 drinks, she could handle 3 drinks an hour probs since HS, that would not illicit the road rage, and rapidly deteriorating mind set, and crying. She was not crying or fearful because of her ex/current. It was the drug that was rapidly paralyzing her, that's why she was last seen sitting against the wall, every roofied person has to lay down or prop themselves up, after paralysis they're helpless. I believe one of the people Prisma called answered and told her he'd meet her on the roof, as they'd done in the past, the lady who saw her next to the silver car w the trunk open said she'd seen Prisma on the roof with another man previously. As for who slipped her the roofie, I've been in the restaurant biz, for some reason some restaurants are notorious for this activity, not accusing any staff of the restaurant Prisma was last at, but it's an epidemic in some areas, I believe the person that told her to meet him on the roof, as they'd done in the past is our guy
In your scenario (which is as good as any) we obviously need a list of everyone who was in that building or parking lot that day, but don't have any way to get such a list. It wouldn't have been the guy who served her drinks, or anyone in the bar (because there's no connection between the bar and the apartments), but rather just someone random who wandered by, and maybe not even someone she knew before.
It's probably worth mentioning that LE has video of her entire time sitting at the bar, and they say they didn't see anyone slip anything into her drink.