The door is already open, or at least one of them is. It would be far faster, no matter who is hacking, to go for the open door. However, once the shooting has started, there is no cover for anyone, so it is best to get out as quickly as possible. The hostiles don't have stormtrooper aim. The barrier will help, but it is going to be under a lot of fire very quickly. You can choose who lives, as long as it's not [i]everyone[/i].

Unless people come up with a combination of solutions that end up being very reasonably effective, then there could be more survivors.