Even bending over backwards they were barely able to show a tiny correlation from surveys. Meat consumption was the evolutionary step that enabled primates to develop and maintain biologically expensive brains that made them human. There unquestionably had to have been a strong evolutionary pressure to adapt completely to meat eating.
This is just data dredging in pursuit of justification for some kind of weird anti-meat sentiment which has been growing for decades, when the real culprit is already known - it's the sugars that have most likely been killing all of us, although to be honest if the same "gold standard" methods were applied to sugar related studies I'd question those as well. The way the media continues to sensationalize these correlative, broken studies is shameful.