OK, this is going to get a bit lengthy but here goes:
1. You can argue the definition of "trace" if you like, but Houlihan was 2.5 times over the limit and therefore, it was clearly not a trace amount in her system no matter how you dice it.
2. Sure, Schumacher may have been ignorant of nandrolone, I can accept that. It would be odd for a guy who's been a pro coach since 2008 to be ignorant of a substance that had led to other athletes testing positive for doping but maybe he's the kind of coach who doesn't pay attention to detail...
3. The jury isn't out on the benefits of nandrolone. It works by delivering more oxygen to the muscles via the red blood cells. Why is this beneficial to runners? Well, lack of oxygen is one of the reasons that we produce lactic acid. More oxygen to the muscles means better lactic tolerance, or an improved ability to operate at faster speeds for longer. On top of that, nandrolone aids muscle building which is useful to mid-d runners, and recovery which is beneficial to all athletes.
4. The claim is unclear, and that's part of the problem. Even their story isn't easy to read.
5. Agree that the study is imperfect. It's not being misrepresented, as you say, but it's not definitive being based on a sample 3. I didn't see anything in the study to say that you have to adjust for the height or weight of the individual, maybe you can provide a reference?
6. The article is old but things haven't changed much and castration is still the norm
https://www.avma.org/resources-tools/avma-policies/swine-castration7. Yeah, performance jumps do happen, normally I'd expect to see them a year or so after an athlete goes pro when the new training kicks in. Houlihan's occurred three years later which raises the flag. The performance jump on it's own raises an eyebrow, but combined with the failed doping test, we have a serious cause for concern.
I'm totally open to reassessing the evidence when presented but what we have now is a string of really remarkable coincidences or appalling luck. It can happen. In any case, I just want us to think critically about this. Facts and evidence first, your feeling for whether Houlihan is decent or honest left at the door for now.