Eff GitHub, but that's probably the most ideal reaction to the issue. Ideally, that DMCA wouldn't have gone through in the first place. DMCAs would have been explicitly vetted in the first place, rather than issued by an automated system that inevitably would be abused by copyright fiends. To say they couldn't anticipate such an outcome, you'd have to be an idiot.
Services like NotABug and NonGNU wouldn't have this issue, because they're much more preemptively scrupulous about the proper and explicit licensing of their projects.