If he wanted for the code to be available, though, he could give it to someone else (who doesn't work for a GPU company), and that person would then release it (and would own the copyright).
He would not gain more "reputation points" because his name wouldn't be linked to the project, but that would avoid for the code to be forgotten in the cellar while nobody cares.
Yeah, you could always try to circumvent or work around the company lawyers. But quite frankly, it's not a gamble you want to take when you've got wife, kids and a mortgage to worry. And a job you like. It's just not worth it for him to try to make it happen.
I've tried to encourage him to try to convince the company lawyers to give him the OK to release it but he's no too keen. Like most engineers, he is allergic to lawyers and isn't too interested on sharing the code anyway. It was "just" a learning experience for him.
He would not gain more "reputation points" because his name wouldn't be linked to the project, but that would avoid for the code to be forgotten in the cellar while nobody cares.