I wasn't paying attention to the bit about the outer walls because I'm not really concerned about that. It was more about getting sucked into the hole when the AoB is supposed to prevent that. But maybe I misinterpreted this?
You'll still get sucked into the middle, but the game doesn't recognize it as a game over... You have to manually end the game or you'll just be stuck there. That's what the note under the code means about it not killing you - the code won't prevent you from getting sucked in, it just prevents the actual end of the game. Hope that cleared things up a bit =)