Hi there,
While at the plant, I had a chance to talk to a couple of different engineers, and they had told me that they have a man there who does squeaks and rattles, and that of the one that they have seen, loose shock mounts have happened.
This is not to say that it is a common occurance, however, it has happened.
I feel you did the right thing, that the retorque did the trick, and that you will be fine.
Please keep us posted of any further developments, c4c5