Mozilla doesn't claim it has 1B unique users downloading it once without patches.
They are running on their own track, they decided the rules and now some guy comes in and says, on your track you have to follow rules we decide.
No microsoft. It doesn't work like that. They never claimed something that is probably not true. They never claimed unique users. You just want to get in the news and try discrediting them for an achievement they gotten fair and square.
And yes, MS probably has a lot more downloads. But they never made claims and tried to fuse it with their OS, so their downloads is lower anyway (most people get it from the install cd, only updates).
Mozilla and firefox are just busy with a lot of unique downloads on release day and a lot of downloads total. That's the way for them to do marketing. Let them and play your own game MS. You have been doing fine, no need to drag the competition in the dirt. Guess MS is feeling Firefox getting closer and closer and losing the browser war they had total dominance over.