Heh, I'm not surprised. Rare is a service manager, or service tech for that matter, that is genuinely knowledgable about their job. It's just a 9-5 grind with a lunchbreak for the majority, I'm afraid.
Very rarely I'll meet someone on the consumer side of the automobile industry that is actually into cars (you know, subsrcibes to a bunch of car mags, spends some time behind the wheel at a track, wrenches at home on a project, etc).