"...The team excluded the possibility of evolutionary diets consisting of more than 70% of energy from animal foods for two main reasons. First, during the main part of human evolution our ancestors did not have the technology required for hunting the largest, fattest game animals, or being top carnivores, and more likely depended on scavenging for most land animal meat. Scavenging does not often supply large amounts of meat or fat simply because obligate carnivores eat those parts before humans get to them (something I will discuss in the next post)....I find this uncompelling. As Prof. Dan Lieberman shows, humans are uniquely adapted to a carnivororous role. We've likely been the dominant carnivore for at least 2 million years and for 1.8 million of those years, we were catching large animals without weapons.
"...In other words, despite having more advanced technology than had by human ancestors 100, 000 years ago, modern hunter-gatherers typically do not obtain more than 35% of their food from hunting...."
The Megafauna extinctions have been going on for a very long time, and correspond with humanity's spread around the globe. The most likely cause of these extinctions is human predatation of the "largest, fattest game animals".
Given the blind spot in the Paleo community for the unique human adaptation to hunting via endurance running, it's not surprising that Eaton, Cordain, & co. ignore this aspect of human behavior, but I don't think it's good science.
But of course the entire exercise is hypothetical, although interesting, as it's not possible to know exactly what our ancient ancestors ate. Likely it was a large range of foods, as available, but meat was pretty clearly a regular item, and it was not scavenged.