It still seems that it is you who fail to understand the WSJ article, as well as the "legal" standards and consequences. The CAS simply ruled that, in their subjective opinions, based on the limited evidence before them, Houlihan failed to establish her innocence with specific and concrete evidence to the standard required. This does not factually establish that she is guilty of intentional doping, even if the Code requires punishing her as if she were an intentional cheat.
Looks like you are quoting Rachel Bachman, and attributing that quote to Houlihan. There is no absolute abandonment of the claim of nandrolone from a greasy burrito, but just a reconfirmation (this is not the first time she said it) that she didn't really 100% know then, and still doesn't know, as she also suspects maybe it could have been vitamins. When I say the source has not been identified, that is equivalent to saying no one really knows for certain where the nandrolone came from, including Houlihan based on her statements. It's just that the rules give the benefit of the doubt to the accusers, rather than the accused -- that is one of the ways the Code is weighted against the athlete, as opposed to what happens in real courts that enforce civil and criminal laws.
The CAS findings are not even factual in a legal sense. It is a final binding decision, but not necessarily fact, nor based on facts. The CAS found the evidence for pork was insufficient to overcome presumptions in the Code, and based all of their relevant findings about "doping" and "intent" solely on presumptions in the Code. The evidence for an Amazon purchased nandrolone product is completely non-existent. The CAS rightly called this proposed alternative a "suggestion", rather than a finding or a fact. It was suggested without any supporting evidence, and not established to any legal standard.
In a real court, based on the law, the AIU would have to prove with evidence that a violation occurred, and a court would have to rule that the AIU met that burden, rather than turning the tables on the accused, to establish that a violation didn't occur.