> If a random guy said “I’m a woman,” would that have to be enough?
The whole point of the "testosterone level below 10 nmol/L" was to provide a solid line on this so that the answer would be "yes, with caveats".
10 nmol/L of testosterone is right at the lowest level for a male and is WAY higher than normal for a female.
Quoting an article about the IAAF study (https://sportsscientists.com/2017/07/testosterone-performanc...):
> Among the 1332 females, 24 had T levels above 3.08 nmol/L (remember this is the 99th percentile in a previous study).
Of the 24, nine were diagnosed as having a DSD. Nine were found to have been doping, and six were “impossible to classify”
Translate "impossible to classify" as "doping, but we can't prove it so we'll get sued if we say it."