Just googling his bio, I don't think he does. At least it doesn't appear to have been a major component of his career. Even if he did some sports work in early days, hasn't be for a really long time (someone please correct me if I'm wrong here).
Agree completely, though, that he handles sports-related interviews really well. It's partially why he is so successful at what he does (he didn't just hold on to Andy Barrie's audience, but he built on it). A good morning host needs to be able to do great interviews whether the topic is political, social, economic, sports-related, cultural, etc.
My point was merely that CBC Radio reached outside of the sports division for hosting of its Olympics coverage, and gave the job to someone who is not a sports host or journalist and without a background (or with a minimal background) in sports journalism. All I was trying to say by that is that it shows that Galloway's career trajectory has expanded beyond the morning drive show (in support of Andrea's point), and that the CBC obviously thinks highly of him and his abilities (which he has proven, as Wisla notes) to have reached outside of CBC Sports to give him such (what I imagine to be) a plumb assignment.