clearly you didnt read or understood my post.
I said any rock would change the moons momentum. Hence any Rock would change the moons orbit, too. However there is no need to assume the moon would then crash into the earth or just fly away. Why cant the moon just keep orbiting the earth in a (slightly) different orbit?
Hence, lots of rocks and meteorites could have hit the moon, and changed the moons orbit, but not completely thrown it out of it. Even if that object was as large as the moon itself, depending on speed and point of collision the object(s) that we will have after such a collision could still orbit the earth.
I dont exactly know where we're going here.