I thought the same thing. 75mph impact to the left rear quarter would have sheared the entire ass-end off the car. It is plausable that he lost control at 75, slid sideways and decelerated to the poiont where he made contact.Theres no way you were going 75 when you wrecked. You would have done way more damage than that.
In truth, he was probably traveling 30mph at the point of impact (if that much).