If you're trying to view the video under Windows, you'll get an error that says, "You need to install Flash Player to play this content. Download Flash Player now."
Tip: Install a browser add-on to change the user agent to report "iPad" or another platform for which a Flash Player does not exist. The video will then play. I personally use the Firefox extension called "User Agent Switcher" which works well.
It's so ridiculous that we have to do this. I thought Flash was dead. I'd like to ask the BBC's web developers why they don't just show the non-Flash video if Flash is not installed in the user's browser?