I created a separate table for the same films drawing on books that represent the film noir hardboiled paradigm.
The contrast, predictably, is striking. If you consider film noir narrowly, and erroneously in terms of hardboiled criteria, Undercurrent is virtually unrecognized. On the other hand, if you consider film noir broadly, as the reference books do, then Undercurrent is present with one exception (ChiBob's book).
What one thinks of the film, of course, is a different matter. But to the question whether one thinks it is a film noir, the answer may be based on how one "sees" film noir.