Ken Forkish's Pain au Bacon substitute olive oil?

  I made the bread exactly per the recipe and it was delicious and had the best crust I have ever made, even from his other recipes in Flour Water Salt Yeast.

I want to make the same bread except with olive oil for vegetarian friends who will be visiting.  Will the result the same or is there some special property (other than taste) that make the bacon grease necessary.  I might or might not add something to substitute for the bacon itself -- nuts? olives?