Seems to me that we're more likely to remember instances where the expert consensus was wrong than instances where it wasn't. The consensus among Classical Greek natural philosophers in 300 BC was that the earth was round, and it turns out they were absolutely right.

And I can only pick that out as an example because of the later myth regarding Christopher Columbus et al. There are probably hundreds of cases where consensus, rather than being overturned by some new paradigm, withstood all challenges and slowly fossilized into common knowledge.