Yes they made a video with unsubstantiated claims which were even out of date by the time they made them. We'd been talking with mojang before they even bought that up and it was sorted. The code was never malicious, could never harm anyone's computers and the whole thing was just turned into a try-hard publicity stunt by 2 guys who should have known better
I'm sorry, but this is no reason to force a copyright takedown of a video. According to Minecraft's EULA, when you make a mod, "you must also let us permit other people to use, copy, modify and adapt your content. If you don‘t want to give us this permission, do not make content available on or through our Game."
The copyright system is for taking down videos that... violate your copyright! When you file a copyright claim to youtube you do so under potential penalty of perjury if it's misleading. If the content is not directly violating your copyright, do not use the DMCA system. There is no other even slightly valid reason for using it. Is their video wrong? Contact GameChap and sort the issue out with them instead of abusing a system that can destroy somebody's YouTube channel. You might want to watch this video by TotalBiscuit (https://www.youtube.com/watch?v=QfgoDDh4kE0), which spells out the consequences for YouTube gaming press as a whole when the system is abused. If a video is misleading, there are other ways to ensure that the false information is no longer spread that don't go as far as forceful DMCA removal. I would like to hear your reason for using this system specifically, because Mojang's EULA clearly spells out that they had every right to show your code.