That is normal. When moved, they have to rebuild their tube by secreting a mucus which bonds with the surrounding sand. The best thing that you can do is feed it really good over the next few weeks so that it can recover from the stress of having to secrete a new tube.
I'm not saying they won't catch things, but I've kept the Atlantic tube anemones for years and I've never had one catch anything that I wasn't purposely feeding. According to this article a lot of the rumors about them having such a bad sting is false.
I've seen small fish and shrimp pull themselves away from them. It's not that hard to get away. And the sting doesn't seem to be that strong. A fish would have to be really small and swim right into the mouth of it.. get a whole lotta tentacles on it... to get caught I think. This is all "anecdotal" of course. My experience is just that and not a scientific fact. I would be more worried about them bothering other corals.
There are many different species of tube anemones. It is possible that some could have a worse sting than others and that some fish could be more subsceptible than others to the sting.
There are many different species of tube anemones. It is possible that some could have a worse sting than others and that some fish could be more subsceptible than others to the sting.