Using glitches is not the same as cheating. A glitch is merely a part of a game that was unforeseen or somehow avoid either by chance or choice--it's not inherently wrong (or even something worthy of discipline/patching) unless it makes the game unplayable or close to it for others (like the underground sentry glitch in gravelpit ptC in TF2).
People don't get banned in SSB for wavedashing, they don't get banned in Starcraft for using the gas trick, they don't get banned in Street Fighter for using a 2-1 combo, they don't get banned in quake for rocketjumping, they don't get banned in tribes for bhopping, they don't get banned in in basketball for full-court pressing, they don't get banned in Guild Wars for perma-SF farming, they don't get banned in TF2 for Bonk strafing, and they don't get banned for using third-party-antagonizing dealings in Monopoly. Glitches/exploits can become parts of games just as well as any developer-intended mechanic, and there's nothing inherently wrong with making use of emergent gameplay. Glitch mechanics are part of the game when you buy it. Whether it was clear or intentional isn't really relevant to its value.
If I sold someone my car that I had grown up with and they ended up using it for parts, it might not be how I envisioned the car would be used, but that doesn't matter--it's their car, and they have no obligations to me or my intentions. Likewise, game players aren't obligated to stay true to the spirit of the developers' intentions (or whatever you want to call it), they're merely obligated to not literally change the mechanics of the game (hacking).
If the glitch is extremely overpowered to the extent that it noticeably removes viable options at high-level play, then it should be fixed. That's as far as it should go. The video I saw looked like it made you auto-grenade on death. That's not something that breaks the game. It might make the game worse, but that's something that should be patched, not policed.
Of course, I could be getting the wrong impression from the video. If this auto-grenade/javelin/whatever thing literally kills people even if they take measures to avoid it, like sniping from a distance or something, that would qualify as making the game unplayable, which would probably warrant discipline.