Assuming its PS4/xbone then its not exactly cheating, but heavy heavy lag. That happens much more frequently during Iron Banner weeks as well. Bungie did ban a few people for doing this in ToO.
Sometimes its not deliberate, just really bad internet connections. Sometimes it is deliberate, you can lag your internet connection many ways like downloading massive files, overloading your router, buying an actual router loadout that causes lag, etc.
On PS3/360 there are of course code hacks/cheats, but the ps4/xbone environment currently does not allow that.
If you see someone like this bring up the player roster (options / lb lb on PS4) and you can see green, yellow, or red bars on everyones names. Red bars means their connection is shit. If the person is disconnecting though you will see the kind of thing you saw in your video, as the server still hasn't sync'd them disconnecting.
