I had 2 mounted archer champions whittling away at an army of footsloggers. When I tried to move one, who happened to be near the edge, to another square near the edge (but NOT over the edge in the cloudy area), the evil automatic pathing system decided to move him onto one of the glow-y retreat squares, and then the game decided to retreat him.
Please tweak so it will never use a retreat square as an intermediate step on the path to an ordinary square.