I just pretend because he was The Sorrow's son grafting the arm on did inadvertently channel the 'spirit' of Liquid, but not to the extent we believed. Ocelot played it up to deceive The Patriots. Let's be honest it was a -blam!-ing stupid plot in the first place, so I can't agree with people who say Kojima ruined it in MGS4. Revolved Ocelot is a much, much more interesting character than Liquid could ever have hoped to be. They should have just brought Liquid back himself. I remember thinking The Phantom Pain was going to be a MGS1-sequel starring Liquid after waking from a coma some years after the events of Shadow Moses. lol