Surface HD snafu: Linux on a PowerBook

I was catching up on some TV the other night watching Surface Episode 12 from last month. Two of the main characters were using a PowerBook to read their email. Being the Mac geek that I am, I was looking rather closely and I noticed that the PowerBook wasn't running OSX. I had to rewind it a few times to catch what was going on, but thanks to High Definition I was able to clearly make out the Gnome Desktop (Bottom left corner of screen and menu bars). The odd part was that although they were using Mozilla to read their email, the message in question was in Outlook Express, it seems like a waste to configure Wine for OE. The clip was long and elaborate and for the life of me I can't figure out why they wouldn't just use OSX for the scene.