This is one truly astonishing film. When I think of projects I've been involved in and the cheap and cowardly ways they cut corners to avoid filming challenging scenes, my respect Alfred Hitchcock's creative courage and technical brilliance grows by leaps and bounds. One time, they got their knickers in a twist over a scene with a chipmunk in it ("Where the hell are we going to find a chipmunk wrangler!")
Most people I know are "gunslingers" who, with nary a moment's reflection, shoot down creative ideas. That is because most people are intellectually cowardly. Not Alfred Hitchcock, who had rare intellectual and creative fortitude. Just watch "The Birds" and you'll see what I mean.