Farah's group hit 5k a little BEHIND pace . 14:48. You said the 1st 5k was a tailwind, and downhill .. they should've been faster, not slower, than their designated time.
Part of the point here is that your premise that each and every group went out too fast is incorrect .. the 2nd group went out a little too slowly. And then slowed further when the wind and gradient changed.
I think Haile's pacing was a little erratic (given conditions, a little, not a lot), and overly fast at the start. Considering he only ran 15k, I'd suggest this is probably correct. Considering he was visibly motioning the group to slow down after 5k, I'd say for sure they went out too fast.
And, for whatever it's worth, this is partly because it's Haile we're talking about .. I'd have higher expectations for a guy of his caliber (whatever that might mean) :) than I would someone else. And it's not the end of the world .. Kipsang broke the CR, as you pointed out .. the question is, as I saw the thread, has anyone heard anything about why he did a poor job. not so much what part of his job was poor.