Simple realy when you think about it. Ok so when you download the game settings it is putting in the step before it trys to connect. So when your playlists and everything are done downloading and checked on the hdd, when you sign out and in quickly it still has all your progressions on your account and the playlists.But because you have just signed in the game doesnt recognize the sign in yet and lets you bypass connecting to the servers. It says you have playlists you must have connected, (the signing in and out leaves around a 10 second refresh rate between psn-Ps3-Servers) so it lets you in the front door. You can play because after u get in the front door there is no reason to check the ban list for you thus instantly connecting to the servers. but unfortunately the "house" has security cameras and adventualy you show up on the same one after around 15 minutes because it re-checks your connection and realizes now that you are on the ban list by running your PSID while checking for playlist updates.

Best answer, ever!
I was wondering this myself as well.
But I love the way you explained it! lol