Do anemone crabs kill each other?

[Robb1821i]

Woke up this morning and found this scene. The one with the cracked shell I just added Saturday. Other is a hitchhiker.
Can/do they do this to each other?

 

[lapin]

Yes crabs will fight sometimes

 

[Robb1821i]

Yes crabs will fight sometimes

I know they'll fight, but his shell is broken. Is that what a molt looks like?

 

[Mr_Knightley]

That looks like a molt to me, it doesn't appear to have any eyes. I would wait a week and see if you find the other one in the rocks somewhere.