Really? Then not only are the engineers and the wardens not the same people, but the wardens must exist outside of the dome, as well. [Every time Chekov thinks that he has a guess about the way all of this works, something forces him to rethink it. How bothersome.]
Exceptionally unusual, then. I didn't find anything useful, either, but maybe something was overlooked? Maybe there was a button that went unpushed?