I guess you are expressing one anonymous man's/woman's opinion.
None of this seems to support the original "Said No One, ever." As anyone can find out for themselves, there has been rather detailed criticism of the analysis and interpretation of the tests, and WADA's response seems to be some version of "Hey, we're WADA. Trust me bro! We're doing it right. Even WADA says so."
Lagat: Note I said "Maybe not the EPO test per se" and again "something wrong with the EPO test results". Lagat's case is not about the test per se, but about anti-doping persons getting the analysis wrong due to factors after sample collection, leading to a wrong intepretation of the test result, and a wrongful charge of an ADRV, and risking irreparable permanent damage to Lagat's career. He is still considered a doper in the eyes of many fans, based on the original faulty A-sample interpretation. Lagat was lucky to have the resources to challenge it. Most poor athletes would not be so lucky.
Colvert: An additional criticism in Colvert's case is that Colvert was refused access to the original gel images when he asked for them. The evidence used to convict him was the post-processed output of software, apparently after the original gel images were cut and realigned. Given the burden is on the athlete to prove on a basis of likelihoods with evidence, and he is denied access to the original unmanipulated evidence, this may help explain why he failed to meet his burden, why he was banned, and why he lost his appeal. (Vojtech Sommer had to pay the WADA lab in Dresden 2000 Euros to get the lab to provide the evidence.)
Biwott: Whether you see a problem or not, other lab experts and advocates for scientific integrity do see problems. Even if we "presume" (there's that word again) the WADA peer-reviewed method is valid, this doesn't address the criticism that the execution, analysis, and interpretation, is error prone, if not invalid. Just because WADA has been using it for 10+ years, doesn't mean mistakes were not made. In any case, the method has been under criticism for much of the same 10+ years. (Prof. Boye and colleagues published an article in the Lab Times in September 2015.)
Note that I haven't expressed any personal doubts here about Biwott's test results (having not seen any of the gel images, and admitting having seen nothing about testing blood for the presence of EPO), but was simply a messenger of relevant information that there are experts who have expressed a broad range of doubts, not only about SAR-PAGE result interpretations, but more broadly about the fairness of prosecutions against accused athletes, in a process defined by WADA.
I did express doubts about "why" a 39-year old, who peaked on the track some 20 years ago, and has road PBs from nearly 10 years ago, would intentionally use EPO at 39. Seems like at this point, his coaching job is more important than any future career as an athlete. I'm even wondering why he is still in the testing pool after 2019. We could speculate he was using EPO all along, as some have, but then his times even in his prime were not really all that good, relative to top national class runners, let alone world class.