There's the story of filming the scene in Lord of the Rings where Saruman is stabbed in the back by Wormtongue.

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.'"

If I recall correctly, Peter Jackson asked Christopher Lee to utter Saruman's loud death-scream after Saruman had been stabbed in the back.

Christopher Lee responded that a person in that position, (due to punctured lung I suppose) wouldn't be able to scream, so it would be more of a strangled noise. Apparently this drew on his experiences in special forces in WW2.

edit: the scene is here https://www.youtube.com/watch?v=0bG8CVUujhs Saruman is stabbed, it is Grima Wormtounge who gets the arrow.

And then the scene was removed :(

More importantly the pun about it being a purely bywater joke to refer to New Row as "Sharky's end" never made it to the big screen.

You know nothing Peter Jackson.

Not in the extended edition!

I remember, from the commentaries for The Lord Of The Rings, Peter Jackson saying that Cristopher Lee used his experience in the war to suggest how to make some death scenes more realistic. For sure he had a varied life.