Absolutely false. Jipcho went out hard as had been the plan. Keino was running 3rd place or so for most of the 1st lap. Not record pace. I don't know if there is a youtube video but i remember in Ryuns book he said he saw Jipcho go out too fast knew he could not hold it. Keino was not that far in front of Ryun in the beginning. Then around 800 meters there were quite a few runners between Keino Jipcho & Ryun. and he briefly lost track of who was who. When he saw Keino in the lead initially he thought it was Jipcho & he would fade, a few moments later he realized it was Keino and he had no hope of catching him. Ryun had speed which he relied on to win. In his prime it was very unusual for him to not finish in a 51 last lap. So he frequently let runners get quite a lead. I think he had expressed many times that Keino would have probably won anyway, but he did get them mixed up until it was too late.
On the contrary, he has stated numerous times he felt he would have won at sea level. Looking at their head to head match ups at sea level, it's hard to disagree.