Anthropologists had long assumed that Neanderthal's were carnivores exclusively and that their restricted diet and inability to cook were major factors in their extinction and that our direct ancestors, Homo Sapiens, survived in large part because of a more varied diet.
When scientists were asked how such a huge error could be made, they answered, "We've tended to assume that if you have a very high value for protein in the diet that must come from meat. But... it's possible that some of the protein in their diet was coming from plants.". Dah. Hunter, gatherer, vegetarian masterchef-Neanderthal's ate a cooked and raw mixed diet of many plants, including wild grass, legumes, palm dates, roots and tubers.
Expert judgment always plays a large role in the assessment of evidence and the conclusions drawn from it. Here is another example of how the conclusions of science, like all human endeavor, aren't objective, are limited by our current knowledge and our culturally derived assumptions and aren't-by definition-a 'conclusion'. To conclude is to end, good science never ends. We each see events through a unique mindset, we triage incoming information to manage the deluge. We rely on the conclusions of authorities to inform our worldview, but to often forget that authorities are just people and people love to apply nice tidy conclusions that verify their hopes and assumptions. Uncertainty is science's only valid conclusion and the hobgoblin of authority.
