If this was a very small six-line, it could possibly have been eaten. I have a very small(1" diam.) bubbletip that can eat large whole frozen krill that are nearly as big as the bubbletip. Anemones do not have the limitation of a skeletal structure, and are very flexible. If you have ever watched one move across rock, you can see just how much they can inflate certain protions of their bodies to move, why would they not be able to use this technique to eat? Also, if you notice, he said only half of his fish was left inside teh casing, and the rest was being eaten, which would of course mean the fish was deceased. I have yet to find normal-sized hermits to be aggressive enough to eat fish while they sleep, but perhaps I've just been very lucky with my hermits. I do have a very large hermit that has been known to eat small fishes, but we're talking a hermit that requires a shell 3" across, not a typical cleanup crew size. lol