I would presume that most papers will include a number of references to sources that the authors have only briefly skimmed, only read the abstract, or not actually read at all.

I saw an article somewhere (I wish I'd remembere where) about a widely-read paper making a mistake when it cited one of its sources, claiming that the source said something which it didn't. A number of later papers by other authors then repeated this mistaken claim, presumably because their authors didn't bother checking whether the prestigious paper was correct in its cite.

I'm about .90 confident that Luke hasn't actually read all of his cites in entirety.