The rider could have easily been crushed under the wheels of the car. I never take the lane when I would impede traffic at a walking speed, THAT will piss off motorists. I cringe when I see that bad form.
You can easily take the lane and pedal at a speed that does not impede traffic at an intersection. And when the lane after the intersection is a sub standard lane like in the video you can continue to take the portion of the lane that keeps motorists from pretending there is enough room and side swiping you like in the video. When I am in a motor vehicle I choose not to run over bicyclists who use bad form like the bicyclist in the video. I don't cringe. I wait or go around them when there is room or an opportunity.