The simple answer is we can’t, we have to trust the expert. But how can we trust an engineer who only crossed the threshoid 15 minutes ago? We can begin by asking a few simple questions and listen to the response we get; not only to the content of the response but also the way he delivers it. Is he talking down to us, or talking in technical terms and acronyms that we don’t understand and checking for our understanding? Is ge telling us stories to demonstrate a point and at the same time demonstrating his track record?