He explains it best himself in this lengthy quote:
"It was a woman… all dressed in black that fell from the tree but she didn't touch the ground, just remained floating several feet from the ground. I saw her very well and then she landed softly on the ground and stood there looking at me. She was trying to cover her face from the lights of the car, I think they were bothering her. I could see two big black eyes on her, completely black without eyelids, and her skin was dark brown. She was all dressed in black with cloak and cape like a witch and she seemed very upset by the lights.
"As soon as I realized it was a kind of woman being, or a witch, very strange standing there trying to cover her face, she threw herself against my car very fast, falling on the car and hitting the windshield. She was flying very fast and it took only a second to hit the windshield glass. I was so shocked by this action that I put the car in reverse and pushed the accelerator trying to get away while requesting backup assistance by radio.
"It was a woman with big black eyes, everything was black, no eyelids. Her skin was dark brown and her expression was horrible. She was furiously trying to get me with her claws while I was running away in reverse calling desperately for backup assistance to any units around. When I finally hit the end of the street, I was so shocked that I covered my eyes and then I fainted."