I'm not sure about the knife but I do know for sure that Sylvester Stallone is a major knife knut who knows his stuff just like all of us. Hell I seriously wouldn't be surprised if he secretly lurks among us here on Bladeforums.
I do remember reading a thread from a long time ago where the owner of a small internet knife store was claiming he got scammed by Sylvester Stallone. From what I read, when Sly was directing the Expandables 2 he ordered thousands of dollars worth of very expensive knives (i.e. Microtechs and several customs) from the owner of the knife store. I guess since he had already dealt with him in the past they agreed that Sly would pay him later on. From what I understand he never received the thousands of dollars Sly owed him for the knives.
I'll try to dig the thread back up.