Would a Caveman Observe the 5 Second Rule?

I think the recent study regarding the "5 Second Rule", which states that an item of food dropped on the floor is dropped is okay to eat so long as it is picked up within 5 seconds, is really unnecessary.

We literally reside in a world of microbes. They reside everywhere on the planet, including within the body. How are plates and forks immune to bacterial growth? Clearly, they aren't. 

How many seconds does food sit on a bacterial-laden plate?

One caveat, however. If food is visibly soiled after being dropped, say on a farm pasture, it's probably best not to eat it. But, the carpet in your living room or the kitchen floor? What would a caveman do?