I'd say he probably meant, "You win if our opponent's contraption touches the ground on his own side", but it's hard to say.
By the current rules, I'd call the question contraption valid - mostly because it's still not an invincible defense.
I came up with this offense pretty quickly which beats it.
http://FantasticContraption.com/?designId=8932991For people looking for the one to beat, it's still Mike's:
http://FantasticContraption.com/?designId=8929332