I agree that the best way to run your fastest in a 5k, strictly physiologically speaking, is with a slight negative split.
However, physiology isn't the only x-factor in racing, especially in cross country. You must consider your competition, the course, your mentality and preferences, fitness, etc. It is impossible to predict the way the race will play out before hand, so you have you to do your best to plan for everything.
In an elite cross country 5k, it is important to be with the leaders somewhat early (in my opinion). No, you don't have to be up there at 200 meters. You don't even have to be there at the mile, but you need to be somewhat close. Perhaps, the best strategy would have been to run an evenly split 4:30-4:35 mile (not a 2:10 first 800, which probably means a 62-63 first 400). Then again, it's very hard to tell what your pace is early in the race, and guys are just trying to stay near the front. They probably weren't too happy to see 2:10 on the clock, but by then it was already too late to really rectify the situation.
But it is important to eventually be "up there," perhaps within a couple seconds of the pack by the halfway point of the race. That is, if you aren't way, way better than your competition. If you're the class of the field, you can race however you want, really. If you're not "up there" then you can't cover moves. In general, you are racing the people around you over the last half of the race. There is a strong mental aspect to it. You also can't expect to make up a 10-second gap and run down a pack of six or whatever over the last mile. They aren't all going to come back.
I used to be all about even splits, and I still am in many situations (almost always in long track events). My mind has been changed by a few years of big collegiate cross country races, and how I have performed with various tactics. My opinion is that it wasn't feasible for someone to go out in 4:45 and expect to win that race. I will go as far as to say that it would have been impossible.