Just in the off-chance that there is still lingering doubt about the authenticity of the video, yesterday I found the spot where it was obviously filmed. Tor 125 on the south side, where I saw a group of spotters.
By an amazing co-incidence, just as I arrived, a Singapore Airlines 777 was beginning its take-off roll - on the same runway. I checked later, it wasn't the same aircraft.
I took a quick video of it, and you can clearly see it's taken from almost the same spot as the original.
Munich Airport, 12.11.11 - YouTube