I think its real.
If you look at the close up of the video input on the TV its VIDEO3, same input that they use. So therefore, if another GC was being used it would have to be attached in the front. Then they show the cable from the GC going straight into the VIDEO3 input.
The only way around this would be to record on a vcr the exact same steps that they went through, then play it back, and mimic all the button press's, ect... Which i think is likely cause if you watch the movie, the button presses look like they match fairly well, plus, its hard to tell in the video, but they would have had to quicly attach a vcr to the back.
Its real. I wonder hows its been done?