Well, according to this, he doesn't! :3
Apparently, he'll only turn when you enter a new area, however I can confirm it's not a route, but just when he's off the screen.
Here's something interesting, though (from the almighty source):
He doesn't turn around when you're on-screen. I've gotten eggs from him when his back was turned because they appeared while he was still on my screen.
So yeah. It's not just coincidence, he'll refuse to face the route when you're invading his "personal space" (a.k.a the screen). But he'll still give you the egg - he just won't show it. :3
Hope I helped. :)
Source: Above Link
(Note: I'd recommend not looking at the source, since it's sort of... bleh... x3)