Olive leaf as a supplement and oleic acid oil are different.
The naming of fats is confusing. I guess olive oil is where they first found this omega nine fat so that is why it is called oleic acid.
http://en.wikipedia.org/wiki/Oleic_acid
In that it is a straight daisy chain of carbon atoms it is in the same grouping as the omega threes and sixes which are also long straight daisy chains.
You will find oleic acid omega nine in olive oil. It has to be extra virgin ideally and preferably in dark glass bottles. Refined olive oil is high in omega six, and may loose a lot of the other chemicals that are found with "untreated" oils.
Here is a link for olive leaf which I have not looked at and do not know much about
http://www.anyvitamins.com/olive_leaf_extract.htm
RB