I sent one of my shield units to attack some bandits and they became a bandit as well! I know there must be mind-control effects in the game because I got an artifact that prevents such things. Is there a way to get my unit back after it has been commandeered?

Thanks for any input!

Well I got an achievement for killing a harpy that had mind-controlled another unit of mine. So it seems the answer is to destroy the unit that initiated the mind-control attack. They seem to like to fall back after they take your unit.