For all the iPhone/iPad people:
To view this video (and all other videos "not available" on mobile), download "McTube Pro for YouTube" via the App Store. This is a free app.
Another tip: When you open the app, click "More" (bottom right corner), then click "settings", then click "player", then click "video quality" and select "720p".
Now you can watch all the videos you want in 720p.