Question re white bean salad with pita crisps

I have a question regarding this recipe that Lorien posted a while back. We've made this twice now, and it's come out awesome both times, but I noticed that the list of ingredients calls for olive oil, while the directions don't explain how to use it. Is this for brushing on the pita before toasting them, or is it supposed to be mixed in with the salad? We've been making the salad without olive oil, and it's delicious, but I wonder if we've been making it right...