It is hard to imagine Hitchcock as being a 'moral' person. Most of his films are about murder, deceits, or even nature's supremacy over higher moral codes. He was even quite a harsh and cruel director to his cast. But many of his films do have some kind of moral overcast over them, either directly in the story line, or the decisions Hitchcock makes to direct these storylines.
In "Dial M for Murder" he chose to follow the moral outcome of the original stage play, rather than change it for the logical one.
His main protagonist spent a great deal of time and energy planning his rich wife’s death. He also seems like the kind of guy who could figure out illogical details.
Yet, he got caught (or Hitchcock got him caught) in the tangle of the missing/switched latch key, which his hired gun had used to enter the apartment to kill the wife.
He should have been able to figure out this deliberate set up.
I think this was Hitchcock’s dilemma. Should he let a cold-blooded killer go free, or should he manipulate the script to provide an illogical, but moral outcome?
I am glad that Hitchcock stuck to the original.
I think all artists grapple with this dilemma, but the enduring ones will sacrifice logic for some sense of higher order. I thinks this may make their works imperfect, but they attain an excellence that logic alone cannot provide.
Fast forward 44 years with spin off "A Perfect Murder" and we find both a lack of logic and a lack of morality in this 'updated' version.
I wonder what this tells us about movies of the day?