If just the dish itself came off, it is pretty light, and may of not made much noise at all. I have heard of the dish bolts coming loose, also rusting, which tends to make me want to dob sealant on them. Do you think that would interfere with the function of the dish?
EDIT: I just read some info on the recall. It looks like the whole darn thing can come loose due to the layup of the roof. They ran out of I believe Luan and used something else which evidently is not strong enough to hold the dish in place. So they are adding some kind of base plate to it.
As I am typing this and thinking, the whole darn roof isn't very strong then. There are a few things up there on the roof, like AC. Hmm.