Nothing is stopping this person from sending email patches like they do in the Linux kernel project. No sanctions are involved in this person hosting a Git installation in Crimea that the rest of the world can access.
The problem isn't politics. The problem is that programmer culture currently conflates "access to Github" (which is a service run at the whims of an American defense contractor) with "free or open-source software" (which is a spectrum of opinions about copyright law). They are not related concepts, no matter what Github's marketing team has convinced the world.
I therefore agree with the view that 'free software' is a social movement, while 'open source' is a development methodology.
OSS is full of commercial interests well beyond hobby interests. Joel Spolsky pointed that out in https://www.joelonsoftware.com/2002/06/12/strategy-letter-v/ :
> I noticed something interesting about open source software, which is this: most of the companies spending big money to develop open source software are doing it because it’s a good business strategy for them, not because they suddenly stopped believing in capitalism and fell in love with freedom-as-in-speech.
The free software movement is itself political - as are all social movements. For example, the emphasis on end-user freedoms related to copyright protection conflict with the emphasis on worker rights embodied in the Anti 996 License.