even if she’s lying and he was telling the truth, he has lost simply by submitting himself to this test. Burden of proof should be on her
You misunderstood the article - the story is that she is merely challenging him to the test, not that he is submitting to one. You are correct, in this sense, however - if he submitted to it and he passed with flying colors, the spectacle created of him submitting to it would be the story at the time, and the passing of the same would almost be irrelevant - the damage is done. Hence, why this seems to be following an entirely political, rather than personal, pattern...in addition to the fact she appears to have not offered to take the test herself to bolster her accusations as true - that’s something she can control and doesn’t have to “challenge” anyone to do.