Yes, the turtle flee from the side opposite to the rock you bring near. I managed to make it flee down, but I guess there is a way to make it go out of its hole instead of back in. Maybe with a +2 speed I can control its direction... Maybe I will also try to give it food.
edit: if this turtle have purpose, it have nothing to do with the rock. I managed to get it out of its hole, and all I got was a half-turtle standing in the middle of the area.