Bad Ad Physics? - Heineken World Rugby Cup 2007 Continental Shift

The Heineken World Rugby Cup 2007 Continental Shift advert shows Rugby teams pushing the continents together to form a mega-continent. Maybe I’m missing something:

• If you are standing on a continent, and push against part of it, it won’t move at all. Like standing on a bus, pushing against the seat doesn’t move the bus.
• If you’re standing on one side of a continental divide and push against the other continent, both will move apart, equally, in opposite directions. Stand on a boat, push against another boat, both boats move apart.

Bad Ad Physics or have I missed something really obvious?

[youtube=http://www.youtube.com/watch?v=qeL2xRckBVQ&w=425&h=350]

Tags:  Heineken, World+Rugby+Cup