We've never said you can start the client without an internet connection(might be different for cracked versions).
We've said you can play, be disconneted from the server and continue to play the game. Disconnecting the newtwork cable doesn't instantly break your connection and force you back to the login, you can keep playing. It may be a few minutes if you disconnect the cable, but when the servers were having issues people were playing for literally hours before it booted them. In the recent hotfixes they could've easily changed the check times to see if the connection is still active to be lower or it may be just that way when you disconnect your network cable.