He led for a long time in the olympics...then he got wasted when the medalists decided to go.
This is a very interesting race this year and it all comes down to Kemboi's (and the Kenyan coach's) decision making. If he takes it out fast (7:58), the only person who will be there in the end is Koech, but the faster it is, the better chance Koech has of winning.
If Kemboi lets it go slow he's going to have to test his kick against Kipruto and there will be traffic in the form of Benabbad, Mutai, and Jager, all of whom could medal.
My guess is the Kenyan coach says "go fast." Then Kemboi and Koech will take gold and silver (not necessarily respectively) and of the remaining four medal threats, two are Kenyans, giving the team a good shot at a sweep.
If they go slow, there's seven guys who will be there in the end, with the best kickers being the medalists and there could potentially be only one Kenyan on the podium.