[derbOac]

The problem he mentions happens in science too. It's interesting to see it manifest in history, but it's well-documented that retracted scientific papers continue to be cited as veridical at high rates long after they've been retracted. I've personally noticed papers being cited for things other than what they actually say as well (someone posted an article to HN not too long ago about a particularly amusing example of this but I can't recall it very well).

It doesn't really undermine what the author is saying, but I do think it might be one of these cases where errors in citations reveal something more fundamental about citation process in general. For example, I can also think of shifts in who gets cited on a point, as if something is a new discovery, when it's really more fads in who is prominent in a field, and people "discovering" something by virtue of reading it for the first time by a specific author. The common denominator is convenience or ignorance (not paying attention per the author), which has implications for many things, not just factual errors per se.