In my opinion the Video is mostly shot at normal speed. There are few moments that it might be slightly slowed down. But that level of scale driving can definitely be achieved in real time.
I had an Axial SCX10 few years ago and it behaved even more realistically then the traxxas in the video. All i done is upgraded to the Axial aluminium shocks with no oil, with very little to no preload on the springs and a some wait to the frame till you are satisfied with the results.