crayfish injury

Hi guys, my two-year-old crayfish molted last night but something went wrong. As you can see from the photos, it looks like part of the old shell is still there and has created a kind of "bubble". Has anything similar ever happened to you? Any suggestions? The water levels are in the normal...

I have two crayfish. The big ate off the entire fin like thing of the small one. Now the smallone lay down with no moments. Not at all. Is it dead?