My horse got injured by an aggressive deer?

I am absolutely having a vet come out and take a look at her wound, because it is really bad, but I am very bewildered over how it happened and am wondering if anyone else has ever experienced anything like this before? I have a young mare, barely 2 years old, who is insatiably curious and often getting herself into trouble, however I think this takes the cake. She was being social with some deer on the other side of her fence, and got a little nippy...well the buck in the bunch literally turned around and went at her, and now she has a really nasty gouge of skin ripped out above her eye as well as a puncture where the tip of his horn went into her flesh.....I have never seen anything like this before. It probably looks worse than it is, and at least he didn t take her eye out! Has anyone ever seen or heard of anything like this happening before? I ve of course been panicking a little until the vet gets out here, but holy cow. I ve never seen a deer to anything like that to a horse before.