She is not alone. Many people have difficulty when put "on the spot" around the conference table or in the boardroom. I call it the "hot seat effect" and it is one of the manifestations of being trapped in the Speaker's Bubble (see my explanation of that peculiar place here). I work with clients to climb out of that trap by practicing breathing to stay centered and focused. The insidious thing about the hot seat, though, is how unexpectedly you find yourself on it. You're not standing under lights at a podium in front of a group of thousands, for heaven's sake; you're doing something fairly routine. Sitting in a chair. Having a meeting. But when the stakes are high (i.e. Very Important People listening to your every word), the heat is on.
The way to turn it off is to slow your heart rate by breathing fully and deeply. By doing so, you re-energize while you decrease your level of nervousness. The added bonus is that you regain your focus, and with it, your confident posture and vocal tone. You have the tools to climb the mountain.
My client, however, was worried that, though she could regain her composure, she had lost her way. Her destination seemed oddly distant on her mental map. She "went off on a tangent" while answering questions. She did give definite answers, eventually. But she feared her roundabout way of arriving at them would diminish her in others' eyes. Her misgivings were well-founded: confusing or long-winded answers can make those around you question your authority.
I have worked with her for a while now, and knew exactly what the trouble was. I prescribed a simple mental shift: she needs to trust herself. Trust her knowledge. Trust her clear, simple answer. Because the people she is speaking to trust her. They regard her as the expert in her field. So her desire to explain her answers, to make a strong case for them, is simply unnecessary. Her straightforward opinion is all that is needed. I reiterated: "Trust yourself. Your peers respect your judgement, your expert opinion, your guidance. If they need you to back up your pronouncements, they will ask. . . " But I doubt it. When she trusts herself and gives a clear answer, they will be more than satisfied.
Trust yourself: simple to say; hard to do. Get started!