I personally was there and heard it with my own little ears. Disbelieve if you want, but which part strains credulity? You are correct, though, that I have a belief that sometimes a career benefits from some relocation. I have also personally been present for hiring discussions where this exact issue is raised, most recently just a few weeks ago. It does have a real impact — it would be easy to overstate that impact, but it would be silly to say it doesn't exist.