But you're playing arm-chair quarterback. The choices seem bad in retrospect because they lead to the character's death. In the moment (especially when, like Dallas, you're panicking in a vent with no clear understanding of where the Alien is- and going up requires you to wait for the vent to open back up) you aren't going to make the right choice unless you have the precision decision making abilities of an perfectly programmed computer.
Bear in mind that this are just a mining crew- they aren't trained to handle these creatures or situations and are completely flying by the seat of their pants, often unaware of just how deadly and serious the situation is.
