Sounds similar to mine. Was driving up a ~40 ft hill and caught the back wheel on a vine, turned the entire thing sideways and last thing I remember is saying "Oh ####" and trying to bail off the high side. It rolled down the hill, I came off it, and as it flipped down the hill it smacked me several times. I landed on my back, and it landed upside down on top of me. My brother was standing at the bottom of the hill and rolled it off me and managed to wake me up. I tore the bottom third of my right earlobe away from my head, chipped a tooth, and had fractured skull but other than that I was fine. He was freaking out because he couldn't tell I had torn my ear, he just saw blood coming out of my ear so he figured I was dead.
I should also say, my brother was 15 at the time and about 150 lbs soaking wet. He lifted a Yamaha Grizzly 660 off me by himself. Adrenaline will do crazy things...