Yep. There was a great article a while back about how the Start button orb for Windows 7 and the Start button search box (one of the best features of modern Windows) were thought up and programmed very quickly, but took several months to be properly implemented and debugged because of management.
Tons of stores sell games early. Though I guess that anyone getting banned who have a legitimate but early-sold copy would be directed to take it up with the retailer that broke the original release date, which makes sense.
Microsoft has Account and Console bans, and it has variations therein; there can be a total console ban that extends to all of the accounts on it as well, there can be temporary console bans, full eeprom ban, etc. as well as simple account bans.
It's also unfortunately not a perfect system. On the original Xbox, there was an autoban trigger for an inordinate amount of negative feedback on an account. It made for some interesting retaliations when you utterly destroyed someone and their friends in a game.
I've seen several pictures of opened copies (could be fake, sure), and Halo 2 was shipped to retailers several weeks before release (but that was a long time ago and their policies may have changed in that regard) and had a similar problem to this.
IIRC they banned people who tried to play on Live, but not people who were signed in but playing singleplayer. At least, that seemed to be the policy.
So do they distinguish between pirated copies and honestly-bought copies, and ban appropriately, or do they take the blanket approach of banning anyone playing the game regardless?