I see. Probably can happen to any of us. I routinely descend at 30 mph and many times in a group. I try to stay away from the shoulder and am pretty hyper focused. In fact, I back off on some of my descents because of an over active imagination. One of my riding buddies' girl friend had a 30 mph descending crash that changed her life. I won't go into the gory details...but never far from my consciousness and why my focus goes up proportional to my speed.

All the best in your recovery.