Butler sustained minor injuries during filming when the American Horror Story star lit up a smoke, and as a form of punishment, he messed up one of his stunts and smacked MCDermott as payback.
He tells The Hollywood Reporter, "He flicked (a cigarette) into my neck - which was part of the scene - but because I was supposed to be sweaty and I had glycerin (oil) on, the top of the cigarette, the lit part, stuck to my neck. At first, I think everybody thought that I was just being a whiny baby, until the next day, it came up in a big scab. To be honest, I always thought the cigarette was a stupid idea but I let (MCDermott) do his thing, and then hopefully he felt a little bad afterwards.
"But the same evening, we were doing a fight sequence and I had to chop him, and I was supposed to miss. I chopped him in the neck, and he had to go to the doctor! We were even."