@JPB,
The one instance could have been meant as a semi-joke between colleagues - I somehow doubt humor is always absent in meetings. On the other hand, if it's a pattern, that behavior will make a difference for at least some. I've a personal bias towards people who speak their minds, which of course is the apparent opposite of career style in diplomacy. People who always speak in a controlled manner are, to me, controllers, with a pattern of thoughtfulness before speech followed by chosen words. People vary, and too much of one of those can make me wish for the other, and vice versa.