make getting caught in a closing airlock have a chance to remove a limb

[Technature]

The crushing door is bad enough that it can effectively kill you if it happens at the worst possible time, but not so bad that it's guaranteed to end or ruin your round, and it happens just often enough that it's kinda funny. Adding in limb loss is a really fast way to ruin a person's round due to things they had no real control over.