Originally Posted by WhyFi

Yeah, the hanger is fastened by an external cone/nut. The only role of the frame in this is a hex indent that the hanger seats in to. In the first pic, you can see the gap between the hanger and the stays - that should be flush and seated cleanly, but all that road grime was probably preventing it. The wrench that monkeyed with it should be fired for not taking it apart and cleaning it, rather than just trying to crank it down.

For reference, this is what the hanger looks like when it's clean -