I've got a theory?

So I have galexea that has been battleing tissue loss between the heads. Well that stoped about a month and a half ago when I started noticing the tissue between my button polyp heads slowly disappearing. I first thought they were breaking into seperate colonies (which they may be) but none have died. Well last night I took my flashlight out and was looking around and noticed a whiteish grayish flatworm on my button polyps. But before I could get it out it went into a hole. Well today it came back out and I got it.



Now my theory is that it could have been eating my coral. I have a problem with my coral retracting into their skeletons shortly after the lights are off. I'm wondering if it actually was eating my coral that it could be releasing some toxins into the water but not enough to kill anything but to make it mad and retract. Again this is a theory, I could be 100% wrong. But I want to know if it is possible