Studies can always have confounding factors, of course. And I wrote "falsification" but could have more accurately said something about reducing the posterior probability. Lack of correlation (e.g. with speed) would sharply reduce the p.p. of a simple model with one input (e.g. gas pedal), but only reduce the p.p. of a model with multiple inputs (e.g. gas pedal + hilly terrain) to a weaker extent.