"Nebraska Man" wasn't fabricated -it was a mistake, not a fraud.
True, but Percy is correct that one of the reasons Osborn and Smith, for instance, waxed a bit over-enthusiastic about the find was the desire to "discover" hominids in North America - like the ones that had been found in Europe. Another bit of international "competition" and prestige briefly getting in the way of science. Of course, even almost at the moment it was announced by Osborn, there were scientists calling it into question (notably MacCurdy, Gregory, et al).