Idk how thats physically possible tbh.
May we see photos? Are you sure its a condy anemone the crab picked up?
Even aiptasia is too big for them let alone any condy I've seen.
EDIT: I wanted to research before I said it, but yeah pom pom crabs are only known for picking up Triactis producta in hawaii, and in the indo-pacific been recorded with Bunodeopsis anemones alongside Triactis. It shouldn't even view condylactus as a viable anemone. There was even a study with a group of 50 of them and 48 of them all had the same anemone... the other 2 just were noted missing one or more anemones.
If you can provide a photo maybe something else is going on or this isn't really a condy anemone we're talking about.