I was in an accident on 7/30.

I was already in the middle of the intersection when the other car failed to stop at the stop sign and smashed into the passenger side of my truck. I drove the car forward 1)because I had a passenger, my husband, and wanted to make sure he was ok and unhurt and 2) to get out of the way since we're in the middle of the intersection. Allstate, the other driver's insurance company is alleging that was negligence on my part and although the other driver was at fault they can only pay me for 80% of total damages. Can they do that? The total amount they were willng to pay at 100% was already low enough, and I don't think it's right that we only get 80% when I didn't cause the accident.