It's not really a great thing that clowns host in bubbles corals or any LPS
. when the clown is snuggling, the fleshy part of coral might be pushed, rubbed, etc into the calcerous skeleton of the coral causing rips, tears, damage, etc to the fleshy parts.
Did you throw your rose anemone out? depending on how bad the anemone got mutulated it still can be saved. The anemone should be able to pull itself out from the powerhead. Pulling the anemone out yourself might cause even more damage. But you should unplug the powerhead(common sense).
Next time you know now that you should anemone proof your tank by covering the intakes of powerheads, filters, etc with a sponge or something