Not really sure if the road she was on was a highway, but she certainly played a big part in provoking this guy. It's simply common courtesy to stay in the right lane if you're holding somebody up. I would hardly even consider that "tailgating" either. There were a few car lengths most of the way until the guy passed her. Minus the guy flipping her off and crashing, the female is 100% at fault here.
She might be guilty of intentionally provoking the guy by driving slowly, brake-checking him, or speeding up in an effort to keep the guy from passing her, but I can't confirm any of those things happening in the video (they may have happened beforehand, we don't know). The guy was still the one, and ONLY one, responsible for actually crashing his truck though.