The other thing was that so much turned on whether the water tank lid was open or closed when the maintenance man found her. It was very ambiguous, but apparently when he initially found her the hatch was open, which makes it clear that she climbed in herself and makes the other theories null and void.
The police could have made that so much clearer both at the time and now, it's as if they want all the crazy theories or something 
The lift footage doesn't even look like she is trying to get away from someone else, it looks like exactly what it is, a young woman having a psychotic episode.
Also, the other 'theory' was about the parallels with the film Dark Water, that someone was doing a copycat murder - what, so they made her wear a red jacket so that it would be 'the same'?
It's far more plausible that she had seen the film and it was manifesting in her psychosis.
In the final episode do they say what the 'strange behaviour' is, that Elisa was exhibiting to get her moved rooms?
The LAM ELISA test thing was a bit weird, but I imagine that the TB theory originated from that iyswim?