Amen to that, i had two watches with Valjioux 7750 base movement that have similar loud noise. if it bothers you so much you might consider taking it to Omega service center and ask if it was normal?Sounds a lot like my 7750 movements.
Why would what he was doing damage the movement?So, I guess this is the first time you have had a watch like an Omega Deville Prestige? Of course, if you shake it, you will hear the rotor spin. My suggestion is not to purposely shake it or you may cause some irreversible damage to its movement.
For what it is worth, it sounds much like my Hamilton Jazzmaster Thinline when I make a quick movement with my wrist or arm.