I know exactly what you're trying to say! Us 'nordic' races just don't have that effluence with words, I doubt that many German unis would have phrased it quite as exquisitely as the Brits. Hehe, at least I don't think I would have.
What you say confirms the widespread idea that you can never really judge how well an interview went. Alright, for my Oxford ones I knew I wasn't up to scratch, and I was deservedly rejected, but for ESPS i thought, like you, that I didn't actually make too great an impression, and yet I got my offer.
Sorry if you may have already said this, but what's your language for ESPS? French as well, by any chance?
In any case, I'm already looking forward to September/OCtober (if i meet my grades). Looks like a really interesting and varied group of ESPS students we'll be!