I think you missed the point of his coding. He doesn't code part time; he uses his knowledge of coding to enable his primary job. I think this is brilliant. When I became a PM I was in a much better position to guide software updates and recommend "easy win" enhancements because of my coding experience. More people need to do this.
I agree - particularly if you are client-facing and working on a SaaS product. You suddenly have someone who is a better pipeline between the clients and the full-time developers.