I don't necessary agree with that as the film does have some film noir elements.
This all sprang from the success of Double Indemnity. This article attributes it all to the "time-honored Hollywood production formula of follow-the-leader", one we're all here familiar with to this day."Of late there has been a trend in Hollywood toward the wholesale production of lusty, hard-boiled, gat-and-gore crime stories, all fashioned on a theme with a combination of plausibly motivated murder and studded with high-powered Freudian implication. Of the quantity of such films now in vogue, "Double Indemnity," Murder, My Sweet," "Conflict" and "Laura" are a quartet of the most popular which quickly come to mind.
Shortly to be followed by Twentieth Century-Fox's "The Dark Corner" and "The High Window," MGM's "The Postman Always Rings Twice" and "The Lady in the Lake," Paramount's "Blue Dahlia" and Warner's "Serenade" and "The Big Sleep," this quartet constitutes a mere vanguard of the cinematic homicide to come. Every studio in town has at least two or three similar blood-freezers before the cameras right now, which means that within the next year or so movie murder--particularly with a psychological twist--will become almost as common as the weekly newsreel or musical."
And as we know, that initial burst, spread through all the studios of the time, carried the trend for years until it morphed into the next stage, where then-current themes like the red scare and the nuclear age became more prominent. This is why I put Double Indemnity as the first noir (when I say noir I think of the initial cycle), anything before that would be a proto-noir, an ancestor. These films, like I Wake Up Screaming and The Maltese Falcon were just randomly occuring crime pictures, like war pictures. I don't see the style in full bloom just yet and being repeated in picture after picture. I tend to put the end near '55-56, because after that, there's really only a handful of films that fit. Certainly anything after Odds Against Tomorrow is affected by the shift that was the 60's and is a different beast and this is where the neo-noir comes into play. IMO"Forever watchful of audience reaction, the rest of the industry almost immediately began searching its story files for properties like "Double Indemnity." RKO suddenly discovered it had bought Chandler's novel, "Farewell, My Lovely." on July 3, 1941. If "Double Indemnity" was so successful, why not make "Farewell, My Lovely"?...MGM excavated from its vaults an all-but-forgotten copy of James Cain's "The Postman Always Rings Twice." The trickle swelled into a torrent and a trend was born."