If you see the side of a car, that is a hazard. Pay attention to it the whole time you see it. If it creeps forward you can hug the opposite side of your lane, if it continues to creep you HONK!, if it keeps creeping you honk brake (don't swerve) and hit them. Don't put yourself into a wall (a rock in this case) if its not your fault.
This completely sucks but it honestly looks like you panicked with a swerve and never corrected, thus impact with rock. I can't even say its the Ford Focus' fault because although they may have creeped forward a bit aggressively they did not get in your way. Don't hate me, I recently got T-Boned at an intersection so I completely understand how fast some incidents can occur. Good thing all are safe.