You would've thought that he would have gone smush on all of those cars and break through the bots...but otherwise sonic team may have indeed mucked up with the boost (it was hardly going down!!) OR the person recording that video
may have just hacked the game! (e.g the ill texture rendering later on in the film)
Actually, I was the one recording this through the console version. But I happened to notice drifting in the air like that can break the stage entirely. (You can stop the rest from rendering if you go higher)