I couldn't watch the video for some reason, but I personally would not take the lane on a 50 MPH road. I would gladly take the lane on a 40 MPH or lower road, but anything above that is a bit extreme.

I often ride on a road that's a single lane each way that has a speed limit of 65 MPH. Sometimes the shoulder gets quite small, but drivers have no problem going around me or slowing a bit to go around me when safe. I don't usually ride that road at night however.

I don't know what the alternatives were for this particular rider, but if I were in his situation, I would have ridden to the right side of the road, barring any blind turns or blind hills.