Yeah, I know. Never claimed otherwise.
Doesn't take anything away though. $400 million USD is a huge amount of money in one week. I don't see how people can downplay that. Well, the usual suspects will always find a way, but seriously. It's a great launch. Any company in the world (except Rockstar?) would be thrilled to sell $400 million USD worth of games and hardware related to ONE game.
I wrote a week, not three weeks. Might've been 3 days then. But GTA 5 was also released to a much, much bigger install base (6-10 times bigger than Halo 5, probably).