Maroon clown issue

[Kingx]

Hey, I got a call from my parents a week ago saying that my maroon clown died. I just got home from college and i'm trying to figure out what happened. She has always hosted this green leather toadstool, but my mother said she saw the clown trying out the hammerhead. Could that have stung and killed her? Could her immune system have been weakened by something before hand and then being stung did her in? I have no other fish. water parameters remained constant before and after the incident.

 

[Kingx]

something else that I forgot to add was the hammerhead corals sweeper tenticals seem to be out during the day now. very unusual because i am used to seeing them at night. They have been doing this for the last few days. Is that normal?