BBM
When I first watched the footage I thought she was hallucinating or tripping (drug induced or not) when she was talking/singing/whatever in the hallway, but after re-re-watching it occurs to me that someone could have come along in the hallway at that point - when she turns and puts her hand on her chest and smiles, it almost looks like she was surprised, but not scared. After all the gesturing and counting (?) she walks slowly to the left out of sight - is it possible someone else was going to the elevator, waited for the "crazy lady" to get out of the way, then got on? So not necessarily anyone who had done anything wrong, but one of the last people to interact with Elisa. They might not pay attention to a missing person report, but "crazy lady by the elevator" would surely jog their memory.
I'm just trying to keep in mind that there could be multiple circumstances, a sort of perfect storm. Ingests a substance or is having some sort of break --> goes to elevator --> encounters someone in the hallway --> leaves and meets foul play or becomes lost. Meaning those things all occurred independently and sequentially. Her demeanor seems to deteriorate over the duration, which makes me wonder if her abilities when she arrived at the elevator was different by the time she left... and ended up missing. FWIW I've been given a laced joint, and I've been roofied, and it's crazy how things go downhill in terms of ability to function once a substance takes effect. I don't know how it works with a mental "break", if you can spiral.
JMO and just-my-thinking-out-loud.
