GTA IV: How to steal an Annihilator without cheating or pigeons

This video shows how to get the Annihilator as early in the game as I believe is possible. The only weapons you need are the Sniper Rifle and a machine gun. You do not need to be able to legally access Alderney. In summary, you get a 6-star wanted level, then lead a police-controlled Annihilator to the top of a very tall building. Due to a glitch in the pilot's AI, the Annihilator will come close enough to the roof of the building that you can shoot the pilot without damaging the helicopter. The police that get out of the helicopter will drop M4 Carbine Rifles when they die.