I don't know much about infectious disease epidemiology, but I'll use glyphosate toxicity as an example from environmental epidemiology. Glyphosate was found to be non-carcinogenic by the EPA, but if you review the literature on glyphosate toxicity, industry-affiliated researchers tended to study pure glyphosate, and these studies were the majority of those considered by EPA. Researchers without industry affiliation tended to study glyphosate in the formulations actually sold in products such as RoundUp, and found much stronger evidence of carcinogenic toxicity.
I don't think a generic data scientist would think to ask the question about glyphosate formulations, as many people at EPA did not.