Why the grenades??
After Cutter took out Forget, he was messing around with the parachutes or whatever was back there. He pulled out a couple of grenades, and stuffed them in his pocket.
I was thinking Rane was going to go for a walk outside the plane with the grenades stuffed in his pants, but nope, he just fell... I've seen a shot like that in other films (House, for example.)
My question is, since the grenades weren't used for anything, why bother showing them, and having Cutter take them along before he went up to fight Rane?