Its possible that Asbel Kiprop started doping when his career started to nosedive. Some athletes resort to doping when their careers start to decline.
In 2016, he finished an abysmal 6th at the Olympics. In 2017 he did not win a single race and failed to qualify for the world championships.
November of 2017 is when he failed a drug test. This was despite the fact that he was told of the impending drug test. And despite the fact that he had the option of skipping the test. The fact that he decided not to skip the test betrays someone who is inexperienced at doping.
He has always struck me as a person with poor judgment. He had several altercations with law enforcement despite being a cop himself.