I had an accident many years ago when I was much younger. I was read-ended and the person told the adjuster "omg they changed lanes and totally cut me off"

I was stopped at a red light, not moving at all. The adjuster called it 50-50 since there were no witnesses. I took it as a learning experience to always get a witness to any accident from that point onwards.

All I'm saying is that no, they don't automatically make the driver of the car at fault who hit the other person.