I do not see it to be either a proof of intelligent design, or a refutation of evolution, to point out that when a living creature loses the need for a particular organ, that organ atrophies and dies.

I'm fairly sure that Hitchens was not using the salamander as "proof of ID", nor a "refutation of evolution", but rather quite the opposite.

If you enjoy reading Hitchens then you must be aware that he considers proponents of ID/creationism to be deluded fools, and would therefore not be trying to prove ID/creationism nor refute evolution.