Why is my coral receding?

So recently i posted about breaking my candy cane corals skeleton and instead of it being on the rok like it usually is i put it on the sand since that seems like what everybody does. Well i looked at my candy cane coral and the flesh on it is receding whats going on with? All my params are in order and every other coral is doing great, but this coral started this ever since i either put it on the sand, broke the skeleton (not the flesh) or when i broke these snails off that live in a tube on them...

 

Could be stress induced. Do you have a pic?

 

removing the vermetids shouldn't have done anything, but any time you move a coral, it will take awhile to acclimate to the new flow and lighting.

 

That must have been it. I think the power head flow was hitting the glass bouncing back at the coral. Will this damage repair itself?