bump. probably no one cares at this point, but as someone who follows elite running...
it's not as simple as everyone is saying; you can't just say "I'm an elite, I want to be in that race." I'm surprised the officials said anything to the contrary in that article, since in almost every major race the elite division is by invitation only. Generally, the public is disbarred from it, because to professional competitors, amateurs tend to be nothing but a potential source of danger, as accidents happen, and because amateurs (I'm talking ones who couldn't compete, but think they can, here) have the potential to significantly affect the outcome. My point: it's generally bad to mix the fast with the slow. Thus, major races, to appease the elites which are bringing them notoriety, generally have a separate start for invited elites only (probably 10 minutes or so before the masses).
So...why can't an amateur's time be considered "winning" if it is faster than the pros? Well, because the pros are racing each other, not necessarily the clock. High level running races are very much like chess matches, and racing someone who started 10 minutes behind you would be somewhat like trying to play a game of chess without being able to see your opponent's queen. The elites can't react to the amateur until it's far to late.
Edit: it also sounds like she didn't actually cross the line first. race awards are based on gun time, ie whoever gets to the finish first wins irregardless of when they started. that's the rules of marathon, and if you actually read the rulebook you get in the race packet, it's stated pretty explicitly.