The solution to debunking (alleged) propaganda is providing facts, and not your own alternate propaganda. You seem to be heavily persuadable by "appeal to authority" opinions of outsiders (a popular fallacy among the uninformed), combined with "appeal to non-authority" second hand retellings (a popular children's "telephone game").
What is not lacking are presumptions, and opinions, but what is lacking are the relevant supporting facts, not only for CAS findings, but also for fan-based conclusions that the CAS did not draw.
1) That is what Rachel Bachman wrote in WSJ.
2) That is what Matt Hart wrote in RW.
3) While it is true that it would be a "tiny tiny" chance generally across the USA for athletes chosen at random, individual probabilities can vary widely based on exceptional facts and factors, especially during unique conditions during the pandemic.
3A) That is what Dr. Skiba said in a phone call to Runner's World - his opinion based on what the CAS wrote.
3B) That is what Ross Tucker wrote -- his opinion based on what the CAS wrote.
3C) Again, something the WSJ wrote, paraphrasing what the CAS wrote.
4) What is Tygart's opinion? Previously (according to the Oreganian) he seemed to be more skeptical of the AIU for not going above and beyond the rules to conduct the fact-finding necessary to protect innocent athletes. Maybe the AIU and the CAS followed the rules -- but these are the rules that can railroad innocent athletes to 4-year bans.
We cannot conclude, as you suggest, that "it's basically impossible to have come from a burrito", because the facts necessary to conclude this basic impossibility in this specific case do not exist.
The fact is that on Day 1, Houlihan said she didn't know, and today, on day 1888, she still says she doesn't know. Despite all your second and third hand opinions and retellings, nothing has materially changed to increase the public knowledge (that's me and you and all the other "fans" of the sport) about the origin of the nandrolone. It could be pork ingestion. It could be supplements contaminated during manufacture. It could be doping with intent. It could be from a greasy beef burrito. It could be something no one has thought of. No way to tell based on all the accumulated evidence. The only way to draw conclusions is to presume them first.
The fact is that the CAS doesn't know enough to support their findings, because they had incomplete information before them and relied on unproven (if not invalid) assumptions (and fallacies), and a codified set of presumptions. Regarding the source, the AIU doesn't know, Profs. Ayotte and McGlone don't know, Rachel Bachman doesn't know, Matt Hart doesn't know, Dr. Skiba doesn't know, and letsrun readers don't know, either.
With just adopting one different presumption, "charged athletes presumed innocent until proven guilty", Houlihan would be given all the benefits of all the doubts, and would not be sanctioned.
If you want to go on and on, try something else than giving me the baseless or second or third-hand opinions of outsiders. Show me some tangible fact, like the Amazon receipts, or the empty bottles in the trash, or testimony from insiders, for the oral nandrolone precursors that Prof. Ayotte "suggested".