Really there's nothing stopping him from being both. He did have significant navigation/cartographical skills, sailing thousands of miles that he had no maps for.

That said he was an English sailor under the British Navy at the start of British imperialism. His voyages were basically commissioned to see if Australia existed and to see if there was an opportunity for new outposts for the Empire. He named landings and places he surveyed and we continue to use those over the Indigenous names.

Also he did try to kidnap a Hawaiian chief, which got him killed. So not the best guy.