If a moron hits you when you're on the freeway due to his tailgating, does your insurance go up even if its his fault?
Anytime anyone anywhere hits you in the rear it's almost automatically that persons fault. Your insurance won't go up even if that person was uninsured. Very very rare that that person who got hit in the rear is at fault. Unless you just stopped for the hell of it, which I highly doubt. No, you're OK. Any decent insurance company won't touch your rates and policy for that.
It shouldn't but insurance companies can be underhanded. I was got dropped after being in an accident that wasn't my fault.