My recollection is that a rocket design was scaled up from one that worked, by people who didn't consider how an o-ring should be loaded in order to function properly. They inadvertently changed the design rather than simply scale it. I don't think Feynman got this wrong either. His demo was because the justifications for flight were based on the fact that failure had a temperature correlation, and they had a model representing how damaged the o-rings would be.
The o-ring failure was a measurable consequence of the joint design failure. The data behind the model didn't go down to temperatures as low as that at Challenger's launch date.
For more inappropriate extrapolation to justify a decision: the data for the heat shield tile loss model was based on much less damage than sustained by Columbia (3 orders of magnitude IIRC).
Now they are looking at the same style of fallacy and don't even have a model based on damage sustained in flights.
Another parallel I haven't seen discussed here yet, though I haven't read all comments: I recall Feynman feeling like he was on the investigation panel as a prop, that the intention of the investigation was to clear NASA of any wrongdoing. They used a model, considered risks, etc. Feynman recognized the need for a clear and powerful visual to cut through an information dump and pull it to front page news. The invitation of Camarda to a presentation with a pre-determined conclusion has the same feeling. I don't know what Camarda can do to put it on a (non-HN) front page today.