This thought came up as I was perusing some posts in rec.aviation.military, where a couple of people tend to post a lot about assumed accomplishments of Nazi engineers. Now, engineers in Nazi Germany made some surprising advances, but because they created the first practical jet fighters and the first ballistic missiles doesn't mean they solved antigravity, supersonic aircraft, electromagnetic propulsion, etc.
I have grandiosely decided to name this line of thinking, because I don't think anyone else has. I call it the Tesla fallacy. Because Tesla was a bona fide genius who produced many advances (most notably alternating current), some aficionados assume he must also have been right when he believed that death rays, long-distance wireless power transmission, etc. were possible (and their application has been suppressed by evil government or corporate interests, of course). Not necessarily so.
(For example, MIT engineers have found that wireless power transmission is possible for low power levels over very short distances (anything more and you're sending EM energy everywhere, messing up whatever other electronics are in the vicinity and driving the power needs of the transmitter to impractical levels.)
The point is that even proven authority in a given field of endeavor does not guarantee further accomplishment, even in the same field. Maybe it's not a wholly original thought, but it seemed worth writing down.