I've been asking myself why am I so certain of what I believe I'm seeing in this video. Then it dawned on me; it's my job!
I'm a night auditor in hotels. I've been one for over 10-years, and part of my job is staring at security footage to determine what happened.
I've dealt with almost every kind of situation you could possibly imagine, and the only thing, in my professional opinion, that explains this video is she ran into a paranoid schizophrenic.
I know night auditors have a reputation of being worthless, and most are. I know it's not a glamorous job, but it's my job, and I take it pretty serious. If I was working there, this never would have happened, because I would have been watching the monitors, like I been doing for about 6-hours a day, 5-days a week, for the last 10-years.
I know hotels, I know security footage, and I know people. This is how I know what I'm looking at, and even then this video took me about 2-days to figure out. It's a tough video to figure out.
I'm not a detective in any way. I'd be completely worthless in any other investigation. It just happens that my particular skill set is perfect for this particular case.
http://www.youtube.com/watch?feature=player_detailpage&v=3TjVBpyTeZM#t=90s
1:30
The suspect gives Elisa 20-seconds exactly to leave the 14th floor. Unknown to both, Elisa keeps pressing the "HOLD DOOR" button, and the suspect believes this confirms Elisa is a threat.
In my professional opinion, there is no other explanation to this action. I believe Elisa went to the 14th floor by accident and tried to enter the wrong room. This made the occupant in that room believe Elisa was a threat, and he followed her to the elevator. The suspect gives her a chance to leave, and when she fails to, he believes this confirms she's a threat, and he then takes her up to the roof and seals her in the water-tank.
This is just my opinion, but please consider that I'm not just some guy pulling this from my butt.