Following this on TT today I'm struck so much more by DrU's attitude now I'm focussing on words and not reacting to DrU's manner. I mentioned in an earlier thread that, like many people, I've had to deal with government officials as part of my job. I've always assumed the advice we got in preparation would be extrapolated to any other similar situation, eg courts, police etc. The aim is to establish yourself as a credible, honest source of information. Anyway, the key points are always:
Be professional - ie pleasant, polite, cooperative. Don't show emotion, don't crack jokes to try and relieve tension. No sarcasm or muttering under the breath.
Answer the question you have been asked, no more no less. If your inquisitor doesn't get the information they wanted, they will ask another question. Don't try and second guess them. The answer to "do you know the time" is yes or no. I'm quite a literal person so I find it quite easy. I was once in an audit and got asked "do you have a procedure to cover situation X" and my answer was "yes, we do". Silence. As it was supposed to be a "friendly" audit, I eventually relented and asked "would you like to see it?" after the auditor glared at me for what felt like 5 minutes! 
In my experience, the junior members of staff manage very well - varying degrees of nervousness but they all act appropriately. The ones that don't are invariably senior management, and thinking about it, all examples I can think of are men. Mostly getting irritated and trying to argue back but only succeeding in digging themselves a hole. I can usually spot them well in advance and arrange the seating so I can sit next to them and nudge them when they start going off piste. DrU would be a bloody nightmare in that situation and I'd be doing everything I could to ensure that DrU was not involved in the meeting because DrU is totally unmanageable .