There's very little voluntary about signing up to rules that you're required to sign up to in order to have a career in your field.

The policy position that detection of prohibited drugs at arbitrary low levels should result in a punitive finding, even though it is not consistent with an attempt to enhance performance or with industry standards on permissible cross-contamination, is untenable.

If the goal is to establish the "cleanliness" of sport, then subjecting people who have almost-certainly done no wrong to the same treatment as those who almost-certainly have in fact undermines the moral position.