I don't know the case, but I guarantee you that he didn't just estimate a single variable regression. To establish a robust relationship, you have to throw in all other plausible variables to ensure that the one being tested is what's driving things and not something else with which it is correlated.
It is unlikely you would have heard of this since there was no paper published.
But from the point of view of the company it probably is irrelevant if the variable worked because it was masking another. All it cared about was that the alledged independent variable produced a high R squared.