Well said Keef!
Why on earth wouldn't you shout 'clear prop'? I know I would be more inclined to think of a pilot who didn't bother as lazy and swaying too far towards being unsafe...
It takes a second and may save a life. Never mind about court cases blah blah, it's just common sense if you ask me (you might've guessed I feel pretty strongly about this kind of thing!!)
And if you don't do it because you're afraid it will 'affect your image'...well, what can I say about that?!