Do they use perforce? It seems to be rather popular in the game industry, in part because its model suits projects that have a lot of large binaries in their repository.
Of course -- everyone in games seems to use Perforce. There are no better alternatives, including p4-git, and believe me, I've looked. Subversion is passable but slow.
Even though I use git for all my personal stuff, if I started a console or PC studio, I too would be setting up a P4 server the first week rather than even experimenting with git.
As you say, it seems to be the only code-oriented VCS that also comfortably handles large files (especially larger than available memory) with reasonable speed.
Traditional version control systems consider giant files a user smell.
