Schickel's approach here is largely to address Double Indemnity as the adaptation of a novel, and to compare and contrast film and book, which is an OK if not very original perspective to adopt, but loses any potential interest when the two works are not granted an even-handed approach. Schickel confers Wilder with apparent infallibility, excepting one moment where he oddly dismisses Wilder's high opinion of the original ending, privileging his own judgement despite having never seen the footage in question. He mentions in the acknowledgments a recent (1991, vs. a 1992 publication date) interview he conducted with Wilder as the primary source of the director's quotations included here, but it almost would have been unnecessary to disclose this. There's a fawning, ingratiating quality to the author's treatment of Wilder, as if hoping the director will read it and perhaps think fondly of the critic as a friend; there's a particularly uncomfortable moment toward the end where Schickel recounts a petty revenge taken by Wilder, clearly expecting us to be as charmed by and approving of it as he is.
Meanwhile, Schickel seems almost entirely dismissive tone toward the pulp fiction that inspired film noir, striking the very type of snobbish pose that led the books and the movies they influenced to have to fight an uphill battle for so long (Schickel's dismissive even of some of the respected adaptations as well, for example, The Postman Always Rings Twice). He's more than happy to highlight what he perceives, sometimes rightly, as flaws in Cain's novel while downplaying or eliding several instances of the book's better handling of the material (most notably the less prominent Keyes character, rendering the book a far less moralistic work; Schickel notes this but never allows for the very real likelihood that this change, while it allowed for one of the great Edward G. Robinson performances, also very seriously softened the tone of the film).
In part, this may be the result of a relative discomfort on Schickel's part with literature; only occasionally does he acknowledge the very different needs being served by each medium and the implicit fact that what works will necessarily not map congruently to the other. Beyond this shortcoming, he also devotes time to some inexcusable and unfounded personal speculation regarding Raymond Chandler's personal habits that were profoundly unbecoming and disturbing to read; it's as if, having placed Wilder into the hero role of his narrative, Schickel felt compelled to render Chandler an equally poorly-shaded villain opposite, even going so far as to discredit Chandler's firsthand accounts of events out of hand. (Schickel's questionable method of selectively validating such accounts recurs when in his eagerness to support his thesis, he grants perhaps too much credence to what may well be genteel self-effacement on Cain's part.) It's too bad Schickel couldn't have stuck more to the facts of the case, as those provided the most fascinating bits of information here: the exchange of letters between Chandler and Cain, the fact that Camus's The Stranger was inspired by Cain's The Postman Always Rings Twice, and the anecdote about the use of aluminum filings for a more visually striking approximation of dust.