AAAARRRRGGGGHHHHH....If I hear anymore about the "Golden BB" conspiracy, I think I will have an anuerysm!
1. What you are talking about is an RPG (Rocket Propelled Grenade) with a standoff spike. The reason it was made with a standoff spike is to make the shaped charge from the plasma jet generate enough velocity to pierce. This is MY theory.
2. The shot in question was a VERY lucky (I'm talking about just stupid-can-probably-never-happen-again kind of luck) shot. I'm talking about luck on the scale of a 1:1 bajillion of a chance. This guy shouldn't have been shooting a tank. He should have played Poweball. If it was so lethal, we would have already lost a HUNDRED tanks to this tactic, not just one.
3. The RPG did not "(go) straight through the side and out the other". Think about this for a second. An RPG is a Chemical Energy projectile, meaning that it uses the energey from a chemical reaction (in this case, a plasma jet caused by a shaped charge warhead). It does not use kinetic energy to punch through anything. When the PRG detonates, it effectively destroys the RPG. So there is no way it could "come out the other side".
Take it from me, dude. Look at (1) my screen name, and (2) my location. Without disclosing anything, 'nuff said.