BTA vs. Emerald

[zrr8348]

I have a BTA that I recently added to the tank. It’s been doing very well apart from the occasional fight with an emerald crab. Yesterday during feeding I noticed that the emerald crab’s legs were sticking out from under the foot of the anemone between the foot and the rock. I made a note to make sure he wasnt still there this morning. Well this morning the BTA has a gaping mouth and is struggling to hang onto the rock. Crab still there and has not moved.
I’m a little lost here, is it possible the crab wedged itself there trying to get food, got stuck, struggled, and ended up hurting the anemone in the process?

 

[Webslinger]

let it be, If the crab is bothering the BTA the BTA will move