Why did the Twitch playback [of the Gamescom presentation] suddenly go quiet for an hour?

That's because we faded in some of the local DJ's music and Twitch smashed us. But you can still watch the full presentation with all of the audio on YouTube. But that's what happened to the Twitch version. And that's why we couldn't do a simple export and I was there until 4 o'clock in the morning doing a more robust one because we lost the audio on the Twitch one.