OK, I must admit this has been one [of several] bees under my personal bonnet re paleo eating... this one is about olive oil... simply put, when following a paleo style diet one tries to eat in a similar manner to our ancestors who lived BEFORE agriculture was 'invented'... that time line is broadly agreed to be around 10,000 yrs ago...  the majority of reasons given are to do with evolutionary adaptation to food-stuffs and the health benefits to be gained following such a diet regime [of which I'm a very happy beneficiary]....
HOW does the use of olive oil fits into this?

I've witnessed [on this list] the fierce debate re alcohol and the possibility of people consuming naturally fermented fruits etc. BUT....
anyone here ever seen ancient olive presses?...[I'm talking archaeological ones in the middle east and Mediterranean countries]... the stones to crush the olives are HUGE and have a very precise technology to their design and construction... domesticated [!!!] animals [mostly donkeys on smaller scale production] would turn the stones around etc. 
and then... there's the archaeological evidence showing no production any earlier than 6000 yrs ago ANYWHERE!...

BTW... I'm no paleo-purist and use EV olive oil [in salads only, sat. fats for cooking]

below are some links re the history of olive oil ---

Dedy
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<<Unquestionably the first cultivation of the olive tree world-wide took place in Greece and more specific in Crete. This happened about 3500 BC in the Early Minoan times. 
In this period the olive tree was in wild form but very soon transformed into the form we know today>>. http://greekproducts.com/greek-olive-oil/history.htm

<<The olive.. and the tree which produces olives (olea europea) are known to have been cultivated around the Mediterranean about 6000 years ago.  Its origin could be the eastern Mediterranean, but most probably its origin is from Greece.  Stone tablets found dating back to 2500 BC from the court of King Minos of Crete make reference to this plant>>. http://66.9.187.163/oliveoilfs/11Historia_I.htm

<<Specialists acknowledge that Olive was first a native of the lands of greater Syria (nearly six thousand years ago) before spreading to the rest of the Mediterranean basin. Legend claims that the Olive tree made its first appearance in Syria, in the ancient city-state of Ebla.... located on the outskirts of the Syrian city Aleppo>>... http://www.oliveoilsyria.com/history.htm