Did he plagiarize? YES.
Should he be called out for plagiarizing? YES. (And all of us teachers can use this as a great example when we talk about plagiarism with our students, which for me is the only productive takeaway from this.)
Am I going to be a Zizek apologist on this one? NO.
But I will admit that what is most interesting to me about this whole “scandal” is that I suspect that a lot of this sort of thing goes on in academic journals, particularly when we’re talking about reviews, which don’t really “count” as publications. If we went through every review in every academic journal, and if we scrutinized each and every one, I feel like (and no, I don’t have evidence, for this is a feeling) we would find a lot of language that is repeated without attribution, not because that is ok (for it is NOT) but rather because of sloppy scholarship and, frankly, sloppy work on the part of editors. Honestly, in this case I wondered whether the blog that originally published the language that Zizek used actually got that language from a third source, The Source of It All.