Depending on the task and the familiarity of the user with the editor, it can make a big difference! As an extreme example, a good 80s programmer might work efficiently on a file in ed, but nowadays approximately no human could do that.
OTOH, I've found that having a mastery of Vim helps me out a LOT in interviews where I get a computer to work at. I can actually type faster than I can think at this point, so I get to express my ideas pretty much as soon as they come to me, which allows me to "look more impressive", I guess.
They certainly shouldn't judge based on the choice of an editor or language, but 1) seeing that someone is very comfortable in any editor and any language shows they've been at it for a while, and being able to express the right answer quickly is almost as important as finding it at all.
