The authors of the study are clearly and explicitly aware of this (and other) confounding issues. Do you have reason to think the authors made stronger claims f

The authors of the study are clearly and explicitly aware of this (and other) confounding issues. Do you have reason to think the authors made stronger claims for causality than can be supported by their evidence? In these sorts of study, causality is not simple and is rarely established in one go — it is approached incrementally, as one potential factor at a time is investigated.