It's interesting, but I'm very suspicious of statements like

"Without PFS, Neanderthals must have been simply wrapping the hides around their bodies like a poncho" or "As discussed above, building an animal trap is impossible without PFS"

Spiders can build traps without any language. Birds can build quite complicated nests without PFS. Yet we couldn't because we lack a particular language construct?

I'm pretty sure some things my dog does would be described as impossible without PFS by these authors :) Like burying a bone in one place when other dogs see it, then reburying it in another place when the other dog is in house :)