I think that's the point, and the value of the discussion (hopefully not "argument"). In my imagined best case result, you and your coworker are now having a c

I think that's the point, and the value of the discussion (hopefully not "argument"). In my imagined best case result, you and your coworker are now having a conversation about your backgrounds and perspectives to try to understand where the mismatch is that led to your astonishment. One possible outcome there is that you establish a new, common basis for understanding, and less future astonishment thereby.