See this question in a video!
Our Friend The Expendable Crewman, Part 2

A: Yes. The Expendable Crewman is a real martyr/idiot/klutz who jumps/falls into the line of fire, gets beamed away somewhere (or killed or whatever) whenever someone moves to take any type of Keeper, no matter what the stated action or power that causes that Keeper to be taken or destroyed.

Imagine this scenario:

As your Scientist is attempting to lure the Energy Being into his trap, the clumsy (and terribly unlucky) Expendable Crewman just happens by, accidentally stumbling into the trap, and is captured by your Scientist instead of the Energy Being. You get the Expendable Crewman instead of the Energy Being. Reset your trap and try again next turn…

Or… Red alert! Someone is trying to beam your Energy Crystals right out of the engineering room. Your Expendable Crewman (always first into the fray!) leaps towards the beam… and is sucked up by the would-be thief (some opponent’s Scientist).