I believe this is correct. The Long Goodbye DVD has a featurette wherein Altman expresses pretty much the same ideas, though at slightly lower intensity, and it's quite clear from the ending that the film is a moral reversal of the novel, that Altman thinks that old-school morality (good and...
Absolutely correct; I got the DVD of Long Goodbye a couple of years ago because I love Chandler's books. The featurette is from whence I derived my information. Not a great film, definitely lesser Altman, but not bad. Another one of those "not as interesting as the novel" movies.
People can correct me if I'm wrong, but flashing the negative means, I think, flashing the stock before you actually load it and shoot the scenes, so it's not something you can retroactively "fix," or rather, not something you could easily fix; the process takes out some of the density before...