Wow, this is much more common than I would have thought.
I had a red tail nearly nail me in the head once while in the stand. I caught movement out of the corner of my eye just in time to turn my head. He veered off before making contact.
I'm also a licensed falconer. My first bird, also a red tailed hawk, nailed me in the side of the face last year. My phone rang. I took it out of my pocket to answer it, and my hawk, sitting 15 feet away, saw the red phone I guess, and slammed into my head. I had a nice scar on my cheek and a pretty good scratch right under my left eye.