Naturally, I've disputed the copyright claim, on the grounds of "Fair Use". It is interesting to note that an option in the dispute process is "I'm not using this for commercial purposes". I didn't see educational use as an option, but I suppose that would come under Fair Use as they call it in the US.
So, if you're in Germany, I dunno why, but you probably can't watch the video I'm referring to here. Don't worry, you're not missing much, but the way Youtube is managing copyright is interesting.