> I guarantee if Andreas himself was ever in the situation
> where he had to give a presentation on no notice and told
> to hurry it along, he's almost certainly stutter and repeat
> himself over and over and say the occasional stupid thing.

Indeed, if I attempted to give a presentation on a subject I have no firm knowledge of and tried to answer questions I only have a vague idea what the correct answer might be, it would probably end way worse to the point of a totally miserable fail. That's why I'd never ever give a presentation in such case. I know what I know and what I don't :-)