You've essentially restated what I said above. She declined to investigate certain variables because she was worried they would come out with the "wrong" effec

You've essentially restated what I said above. She declined to investigate certain variables because she was worried they would come out with the "wrong" effects (instead she chose to use near-perfect correlates of those variables, like zip code). You can always decline to use a variable after the fact; she decided she didn't want to know the effect in the first place. Suppose the effect had been the opposite of what she suspected?