though many of the camera techniques are similar, and much of the dialogue is more sophisticated, more cynical even, than was usual for the time. It definitely has the rapid fire delivery that would become a standard in noire screenplays.
And then the use of shadows, the camera angles, are certainly similar to noire. Ilsa's first appearance above the club, the shadows in Victor and Ilsa's room when Victor looks out the window to see "our friend" who's been tailing them, the shadows that fall over her face all through the film, all seem to be precursors to what would become standard to noire.
The Maltese Falcon had come out the year before and there certainly are similarities between Richard Blaine and Sam Spade. Spade's playing both sides -- or all sides -- of the game, and Rick seeming to first reject Lazlo's plea and then seeming to actively try to frame him, is kind of analogous to Spade's relationship to Archer's wife and his rather ambiguous morality. And then both characters redeem themselves at the end, though Spade of course throws O'Shaunessy under the bus, while Rick does the opposite for Ilsa and Lazlo.
In what I think of as pure noire--like Double Indemnity--the leading characters, male and female, are totally unredeemed. The Fred MacMurray character may try to redeem himself at the end, but only after he's committed two murders and believes he might be dying himself.
So I wouldn't say it's pure noire, but it definitely adopts a noire sensibility, at least in the cinematography.
It's an interesting question though, but then I'm no certainly expert at all on the subject.