Why don't they sue them in a Russian court? There are laws against cybercrime there too.
Of course if you're to stay anonymous then you obviously have better chances to stay off radar in Russia than in US, but again that's only work until someone bribe local authorities to find you.
Charged with treason for aiding foreign intelligence agencies, odds are he was working with the FBI and is guilty as charged.
Group-IB was kind of famous for causing problems, it’s surprising it took as long as it did for the government to crack down.
The only "The Untouchable Russian Hackers" who exist are ones who officially work for government, but they are not any different than NSA.