Sounds like it's just shedding mucus (stress from shipping). It doesn't look dead to me. Put it in the tank with some light flow and leave it alone for 24-48 hrs.
I agree about the lights. It will be better off without lights for now. Turn them on for a short period tomorrow.
They can be difficult to kill. I have tried, believe me. I have one that has split so many times that they are taking over my tank. I went in the other night and tried to get one, but to no avail. He sucked in and clung on to the rock with all his might. Having to do something, because he was smothering other corals, I pinched him, cut him, squeezed him, etc, but he wouldn't let go. Mucus was all over the tank, as well as pieces of tentacles, but no issues with anything in the tank. He stayed hidden for a day and a half, but of course he's right back.