Odd occurance with Bubble Tip Anemone...any thoughts?

[newreefer_59]

Was time for the weekly feeding (raw shrimp) of my Bubble Tip Anemone. The first sign was that he grabbed onto the meat, then slowly let it drift off so I knew something was up. He did not look great. An hour or so later, he seemed to be emitting 'clouds' of dusty looking somethingorother. The lights went out around 10pm and he was getting smaller and wimpier by the second while the percula clown was trying to hang onto what was left. I shone a flashlight in several times and the entire tank was pitch black. I figured he was a goner. Anyway, I checked this morning and he looks fine and the tank appears fine too. Any idea what that was?