That much damage couldn't have been caused at 15-20 per hour even if all the wheels had fallen off as he steered directly towards the pole deliberated. It would take a lot of speed in a Porsche GT to lose it enough to hit a pole sideways. Cars don't drive sideways.
Photos of people losing control of such super cars are not rare. It's like driving a car with an auxillary rocket shed motor on the back. I bet the Porsche had performance software upgrading and traction control was turned off. I would bet he "punched" it with traction control off to do the traditional powering into a curve to "drift" around the corner. It would NOT work in that car. You cannot do it with traction control on - the car won't allow it. And you can't do it with traction control off because there is TOO much power if you do. TOO much power can prevent certain performance actions as can too little - but if too much you will crash when it comes to "drifting" - which is very popular in some circles.
I won't say the driver was an idiot. I will say he obviously really screwed up. Like everyone else will do a million times in their life time. But this screw up cost him his life. And that of a passenger. That I can fault him with. You don't drive like a demon with someone else in the car, not around corners.