Maybe they tried but from my experience GitHub does not care one bit about cybersquatting. On the other hand I'm not James Bond so who knows ;)
> Account names may not be inactively held for future use. GitHub account name squatting is prohibited. Inactive accounts may be renamed or removed by GitHub staff at their discretion.
I have been able to acquire a couple of GitHub names that have been inactive for several years by contacting GitHub support, and they usually reply within a day or so.