After the race he didn't seem that happy about his performance, usually when he does a great performance he's more giggly and happy. Now here he seemed just like after a normal win.
I think he expected a crazy fast race given the field, at least a sub 12:45 pace, and he was prepared to run this kind of pace.
IMO, he would have hoped to run way closer to 12:40, maybe around 12:42-45.
And I think if Cheptegei would have run like expected (I think he said he aimed to run 12:40 and maybe even WR pace), Jakob would have been able to kind of use it as rabbit and be pulled to a 12:42-45.