Personally, I think openness is a bit vague in the grand scheme of things. Just because someone is being open doesn't mean they are being honest. Honesty is what is crucial to fraud prevention. How honest, or how noticeably dishonest, a person is can help judge whether they pose some sort of risk to the company. If someone is conditioned to notice all the subtleties that come with lying, dishonest employees would ideally be easy to spot and note down for if and when something like fraud were to occur.