Actually the olive oil does not add sterols, but unsaturated fatty acids (UFA). The yeast still need oxygen to produce sterols.
The yeast take an atom of oxygen to remove a hydrogen to produce the unsaturated fatty acid chain the yeast need to multiply. Olive oil contains oleic acid, which is the same 18-carbon monounsaturated UFA produced by yeast. So, instead of providing oxygen for the yeast to produce UFA, you just provide the required UFA straight to the yeast with the olive oil. But, you still need to oxygenate to produce the sterols.
The New Belgian experiments were not to produce the best fermentation with the least amount of esters. He was doing a specific experiment to see if you could have a ferment without oxygenating the beer to increase shelf life by reducing oxidation in the beer. It did increase shelf life, but the ferment was slower and there were more esters. The slower fermentation and esters were produced because they did not oxygenate the wort at all--something we would never think of doing as homebrewers. At the least we shake up our fermenter. I do not think the experiment was flawed. He suggested adding the olive oil in conjunction with wort aeration, but that would have defeated the purpose of his experiment, which was to specifically ferment successfully without oxygenating. Grady did an excellent job. Buy this is all old news now. I think he said he did this back in 2005...
If I have a stuck fermentation and I need to pitch more yeast, I add a drop of olive oil at the same time. It cranks right off, but I have only needed to do that one time since I have been using olive oil. When I fermented "Cause of Death" I fed the wort daily with concentrated wort I boiled down and I oxygenated at each feeding. Now I think I would just try adding olive oil. I know on the next BIG Mead I want make next it will require me to feed it honey over the fermentation to avoid too high of a starting gravity (which would crush and kill the yeast)--I am going to add olive oil (along with the standard yeast nutrients) each time I add honey.
I hope I said all that correct...
Johnny
P.S. I do add a drop to my brew pot the last 10 minutes of the boil, but don't tell BeerMaker
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