Help! I accidentally chopped off one of my Sand Sifter Star's legs!

New to the forum, but not to the hobby. I've read a lot about Sand Sifting Stars, how they're good, bad, and whatever... In any event, I was cleaning the sand bed last night, and stupidly pinched off one of my starfish's legs. I heard that if one of these things die, it'll nuke the tank. Would this trauma cause death to the starfish, or should it regenerate and be okay? After this happened, it buried itself back in the sand... So here are my options... When in doubt, throw it out (would hate to do that); leave it in and hope for the best. (FYI, I know quarantine is the best solution, but i don't have that luxury at the moment...) Current set up is a 65 gallon Reef Tank with live rock, corals and fish.