After studying the research and methods used to identify exogenous nandrolone use in athletes, I believe the Houlihan case ultimately revolves around the question of corn consumption. The best research study I have read on this topic brings several strands together but also raises questions in my mind: "Excretion of 19-norandrosterone after consumption of boar meat", by Hülsemann et al.
https://www.doping.nl/media/kb/7048/H%C3%BClsemann%20et%20al%202020.pdf
This readable study does a great job of proving that the consumption of boar MEAT, not even boar offal, will lead to the presence of detectable levels of 19-norsteroid norandrosterone (ie., NorA or 19-NA), a metabolite of nandrolone, in the consumer's urine. It is all the more remarkable because the random wild boar meat samples used were most likely a mix of male and female wild boars, and any female meat (50%?) would be expected to have essentially no nandrolone. The WADA technical document (TD2021NA) actually concedes this general point in its most recent version saying, "Following consumption of the edible parts of non-castrated male pigs, concentrations of excreted 19-NA in urine are usually in the low ng/mL range (< 10 ng/mL)..."
Hülsemann et al. also show that when wild boars forage primarily on corn, the level of their δ13C values (ie, the carbon-13 isotope values in the NorA compound found in their urine) is relatively high, between -15‰ to -19‰ and is lower when they rely on other seasonal food sources, down to around -22‰ to -24‰. This is confirmed in another 2020 study "Isotopic carbon turnover in pig hoof and rib" which shows a similar relationship between corn-based vs. rice-based diets and δ13C values in farm-raised pigs (see page 5 graphs).
But there is something puzzling about this study and the WADA technical document. They both refer to WILD boars and obliquely ignore the possibility of farm-raised pigs having tainted meat. Why would this be?
One reason would be the assumption that, unlike wild pigs, farm-raised males are all castrated, and therefore do not carry nandrolone in their bodies. A second possible reason would be the assumption that domestic pigs are always fed a diet consistently heavy in corn, such that even if an uncastrated male pig were to be ingested by an athlete, it would leave a telltale carbon-13 isotopic signature that would allow an investigator to distinguish it from synthetic nandrolone, or from nandrolone produced naturally in the athlete's body in most cases.
For pork sold in many Oregon restaurants, however, and particularly during the pandemic, both of the above assumptions are quite likely to have been false. It is easy to see why WADA would make the mistake, though. With the growth of ever-larger hog operations over the last several decades in the US and elsewhere, it is estimated that about 98% of all pigs in the US are raised in concentrated/confined animal feeding operations (CAFOs). Since pigs are generally confined in these operations, they are fed a mix of grain typically consisting of 85% corn and 15% soybean, resulting in a very predictable C-13 signature throughout their bodily tissues. On the other hand, the small farm operator, who is not trying to compete with CAFOs on price, has an incentive to raise and market their pigs as pasture-raised, and not rely on corn feed, to distinguish them from their factory-raised counterparts.
Supermarkets and fast food restaurants have a great need to purchase pork in bulk with a reliable set of characteristics. One can be sure their purchasing contracts state that no uncastrated male meat is to be sold to them. However, smaller operations such as restaurants, food trucks, colleges, and other local food services can accept a wider variety of meat in smaller quantities, and are eager to market the ingredients in their food as being locally produced and pasture-raised. For them, meat sourced from local farms makes much more sense than buying it from a supermarket or wholesale supplier. It will taste better and inspection rules can sometimes be relaxed for small-time producers, resulting in a lower cost. Oregon (and Washington) residents have a particularly liberal outlook on the welfare of farm animals and negative attitudes towards factory-farming. An upcoming ballot initiative goes so far as to ask Oregon residents to halt the harvesting of farm animals by classifying such slaughter as aggravated abuse and even redefining artificial insemination and castration as sexual assault. In short, Oregonians really love their pigs.
On top of this, COVID absolutely upended the pork industry in Oregon in 2020. Large-scale slaughterhouses in the Midwest were particularly hard hit by the virus, slowing operations, and live pigs from Oregon which previously had been shipped out of state to be slaughtered were now processed in state. At the height of the epidemic, there was so much excess pork in the US food system that millions of pigs were euthanized in horrific ways, with many processed through wood chippers to become compost. As a result, and the fact that out-of-state swine were clogging up Oregon's few USDA-inspected processors, the Oregon Legislature passed a bill allowing the Oregon Department of Agriculture to run a statewide meat inspection program and increase the availability of locally produced meat in Oregon. This development is all laid out in a Portland Street Roots article entitled "Oregon-raised meat could become more accessible locally".
What does any of this have to do with Hoolihan? The δ13C value of the 19-NA found in her urine B-sample was -23‰, which could have led WADA investigators to think the substance in her urine was inconsistent with a confined pig eating corn all day. This carbon-13 isotope value is, however, consistent with a pasture-raised pig, which in Oregon and Washington is how the vast majority of farms raising pork operate, and had become even more prevalent during the second half of 2020 when local meat became more accessible.
All of these rumors and accusations of PED use have started making even me see dopers behind every bathroom door, and I really can't say whether Houlihan and other runners are making use of such substances. If they were, I think they would rely on more sophisticated methods. But I am certain that this one positive finding, under these circumstances, is not nearly sound enough to condemn an athlete for the rest of her life.
In fact, the method of the finding is so lacking in integrity it leads me to think there may be other reasons for it to persist. It is likely that the testing for nandrolone, or even boldenone (another naturally produced substance in male pigs), would result in more false positives from athletes in those countries where pork farming is not as highly regulated and where uncastrated male pig meat is more common. Intended or not, it may be a way to cull the number of top athletes competing from Kenya, where 49% of 182 small-scale farmers in one study did not practice castration on their male pigs ("Characteristics of the smallholder free-range pig production system in western Kenya", 2009). It would seem to be even more risky in Ethiopia, where one study of 90 pig owners found that only 13% of them employed castration on their male piglets "Assessment of Pig Production and Constraints in Mecha District, Amhara Region, Northwestern Ethiopia", 2014). Unfortunately, there is a long history in sport, particularly the Olympics, of using similar practices to prevent lower- and working-class athletes from competing, and this may be yet another chapter in that book.
Many have defended the regulations and processes of WADA, AIU, and CAS as if they were connected to government courts and law enforcement. This is not the case. They are private investigators and arbitrators who work solely for the sports associations which have agreed to hire them. They serve sports, the athletes, and the fans. If that is not what they are doing, they can also be removed, and many organizations have chosen not to work with them. The NBA, NFL, and NHL are among the leagues that have refused to sign on to the World Anti-Doping Code. What do the WADA boosters - who have been so critical of the moral failings of track and field athletes - think of the American athletes who demanded a fair process to handle such cases? Travis Tygart (the CEO of the US Anti-Doping Agency) explained why they did it, in a terrific 2020 article by Andy Brown, "US pro sport sanction issue highlights WADA politics."