Someone ate my leather coral

[Reef Breeder 2013]

So, I kinda recently (around 2 months ago) moved my 20 gallon to a 50 gallon cause I wanted more fish. Unfortunately, I lost many corals when I moved them, so I'm trying to restock the tank. One coral I bought recently was this little leather coral (around 1.5" long), that was doing great everyday.
I came to see my tank this morning and I saw my coral damaged, even though I haven't added any fish in the last week.
My current fish stock is:
1 clown
1 bicolor blenny
3 sailfin mollies
1 coral banded shrimp
Around 4 hermit crabs and some snails

Here is a picture of the coral

 

[Mr. Mojo Rising]

My prime suspect would be the coral banded shrimp.