I think I saw the same, I believe it was from Kayak. They said that an artificial loading time increased the user's perception that the search engine made an effort to find the best deal.
Don't remember the company name but it was a really good talk. But it sounds like it was the one.
Still, worth saying that it's given as an exception that proves the rule that snappier UIs lead to more transactions in ecommerce. The exception was that users couldn't believe that live search in different airlines could be as fast as they made it.