Close reading reveals that in the story, only the robbers claim that he has a wife and no other facts point towards it.

Yeah, I did not have a wife.

I think you are only seeing one side of the issue here. Getting drugged out of your mind and telling strangers your mother maiden name and the name of your childhood pet is just not that common of an occurence. The rare lost $500 may be a worthwhile price to pay, to be able to access your money in a pinch.

Now when we get to 4-digit sums, the balance starts to shift to caution.