I've seen the Javelin video before on the Lockheed website. Judging from the violence of the blast, and the fact that the tank exploded outward rather than absorbing the bulk of the warhead's energy(the turret was launched straight up despite the fact that the missile came in from the top), it almost seems like the target was packed full of explosives--either that or the missile penetrated the turret completely before detonating well inside the crew compartment, which doesn't seem very likely.
Either way, neat vid.