Whispers

[Janakev]

It's an interesting question. Behind the doors is the mess hall and one of the doors inside that is locked. Does it lead deeper into the compound. If so, then I agree with Thaliur; it was most likely used to restrict access to those who were authorised.
However, it could be that the mechanism was used when it became clear the infection could not be contained and so the most vital parts of the facility were locked against those already infected.

As to how the scientist died, well I have one idea. I've just played through the start (sidenote: I too heard "help me") again. Notice in the ventilation shaft all the notes and arrows are in red and coming into the last section there are two splotches of blood on the bottom of it.
I think Oswald was bleeding and using his blood to write the notes and leave the trail. He was probably delirious from the blood-loss and, not realising the severity of his situation, thought he could honestly make it out.