If a magician invited you on stage to and gave you a gun and told you to point it at their head you probably would though right? The audience here are part of the show, and their role in it. Did the people who did things like cut her think of themselves more as actors in an extreme form of theater or audience members?
I would shoot a magician without much hesitation, assuming it to be a trick. Something in this performance was different, I don't think it was a trick.
Not a trick, but the artist's previous works in this Rhythm series were all about suffering, for instance Rhythm 10 and 5 she cut her self, and Rhythm 2 she took medication to give herself a seizure. If you are doing a series on suffering where you injure yourself, the audience is going to understand their role in the performance.