Deer Emma,
While it's generally considered classless to call out a colleague with no evidence, I agree with you 100%. Here's why: Chepkoech got a world record running alone the last 5 laps. This means she had no draft, thus losing about 1 second per lap those last 5 laps. Additionally it is very obvious Chepkoech was not at her limit. She never strained, never grimaced. So you're looking at someone who likely could have broken 8:30 had she been running in a men's race with a winning time in the 8:20s. Had she been running to literally save her life, she may have been able to break 8:20. That 8:44 was nowhere close to her maximum on that day.
One of the effects of EPO is that it allows you to clear lactate much faster, creating a situation where things simply don't hurt like normal. Whoever is advising her clearly messed up and didn't stress that she needed to make it look as if she was actually trying even if she wasn't.
There are rules even within the world of cheating and she broke those rules, which is why she's likely going to get busted in the future if she keeps playing with the jet fuel. Her best bet is to fake an injury, lay off the sauce and come back to running 9:00 range while claiming that her injury can never be 100% healed again, unfortunately.
It's extremely rare for an African-born-and-raised runner to make such a significant jump in fitness at the age of 27.