what twitchy is talking about is of course the elevator hack in mission 3. I've got some problems with that hack myself. So here is some material about it.
As you know, when you go up the several stairs from the basement, you mustn't run because you will randomize the pattern of the alien killing the humans. The usual way to hack the elevator is to let the alien kill the first human at the elevator that is farthest from you coming down the stairs.
First case (best pattern):
Second case (bad pattern):
There are two ways to avoid the alien:
If you're fast: You can hide behind the wall:
If you're slow: You have to wait at the stairs:
If you're really fast, you can go on down the stairs and slide by the alien on breath length. That is really really dangerous. The secret here will be to go to the far rail of the stairs to approach the alien from the side. This way it probably just doesn't see you:
So, there is another strategy I've developed to hack the elevator. You can break the pattern of the alien by shooting before going into the hall. When you enter the hall, the alien screams loudly. A good second after that scream you got to shoot (version 2). It will turn to you and it won't engage the humans at the elevator but the third guy next to it. If you shoot a bit too soon, the guy won't be able to escape and the alien kills it immediately (version 1). The guy always runs away, whether the alien goes for him or not. The farther he runs, the longer the alien is occupied
version 1 and version 2:
The risk involved is that there are patterns of the other two humans you cannot influence. The alien could kill you third after two humans, not fourth after all 3. The humans could stay at the elevator instead of fleeing and running through the room. You can try it out.