Filming a scene in Return of the King (seen only in the extended version), when Grima Wormtongue (Brad Dourif) stabs Saruman in the back on top of the tower, Christopher Lee corrected Peter Jackson on the fact that when a person is stabbed in the back of the chest, they do not scream (as the director wanted), in fact the air is pushed out of their lungs and they “groan” with an exhalation of air, very quietly, as their lungs have been punctured.
From Peter Jackson’s DVD commentary: “When I was shooting the stabbing shot with Christopher, as a director would, I was explaining to him what he should do… And he says, ‘Peter, have you ever heard the sound a man makes when he’s stabbed in the back?’ And I said, 'Um, no.’ And he says 'Well, I have, and I know what to do.’”
The crew said that they knew Christopher Lee had been in the British Royal Air Force Intelligence Service in World War Two, and they didn’t really push him for more information about how he knew in such detail exactly what noise a person makes when this is done to them.
http://wlmager.tumblr.com/post/42350397080/christopher-lee-the-real-james-bond-i-was
