Video Description - Troll Change of Stance - The troll goes from standing to all fours or vice versa. This action seems to cancel out the animation currently in play but only if the troll loses sight of the current target and the animation would bring the troll into the a position where it would have change to stance.
This phenomenon is not exclusive to FoW and can be seen on any other adventure where the criteria provided in the description is applicable. I didn’t feel like going around every map in the game to showcase this so I settled for just the one. Horrible wording but the video is a good demonstration of what happens.
*edit: wrong link