A couple of thoughts: My flight software would warn me, and perhaps not allow me to fly where this flight seems to have happened. I know I can override the software which would make me totally responsible. And, the Video does not seem to represent a flyaway! My flyaway video is dramatic, fast, and obviously out of control.
So, yes, the pilot seems to be responsible, and I’ll leave it up to others to figure out if the fine is fair. But yes, the pilot should be held accountable.
We, pilots, of recreational or Civil UAs, need to be responsible, be accountable, and keep the privileges of flying UA. This type of incident can slant public opinion to restrict our use of airspace.