But what or who is he cheating? If you glitch in CoD you are cheating to win a match. By doing this, is he taking away the world Portal speedrun title from someone? If the rules for the world record (if there even is such a thing) allow for glitches it doesn't matter. If they don't, then this doesn't count. He's really just demonstrating some odd stuff you can do with the game.
They're showing a "speed run". They're cheating at the speed run, which is normally done to show how quickly someone can beat the game within the rules of the game. Using bugs to do this isn't anything special. It's no different than turning on noclip in a game to get to the end and then proclaiming how you made a speed run.