I guess the "PIN" behavior won't follow an ImagePoint, it just keeps position & angle from its spawn point related to pinned object.
I think you need to use a position action on your DOT sprite. So you need to create an event like :
When hunter_img is playing "Attack" > set DOT position to (hunter_img.ImagePointX(1), hunter_img.ImagePointY(1))
This way, every tick, the DOT will be positioned on the imagePoint. (you can also give names to ImagePoints)