What kind of "security" are we talking about? Hotel exterior cameras that are cloud controlled by (probably) a large commercial provider? Considering what is possible with hacking that, and that this is an enormously powerful company, I think it's entirely possible that a hit man could have been involved.

That said, I think suicide is the most likely cause, but we should avoid failures of imagination and consider the possibility.[0]

0. https://en.m.wikipedia.org/wiki/Failure_of_imagination