One correct diagnosis is simply not that significant, except for the woman concerned. The real news will be A/B testing on much larger data contrasting Watson's

One correct diagnosis is simply not that significant, except for the woman concerned. The real news will be A/B testing on much larger data contrasting Watson's diagnoses with those of doctors sans Watson, and checking both against a ground-truth value, if that is possible. Newsworthy would be a marked bump in accuracy across many cases with Watson...