There's little doubt that the Ninth Circuit gets this one right as a matter of legal doctrine. The district court thought that a life sentence was mandatory given the defendant's prior offenses, but that's not in fact true. So a remand's required.
The government says -- accurately -- that the district court would have sentenced the defendant to a life sentence anyway. Which we know because the district court expressly said so.
But the Ninth Circuit's response is spot on. "Because the district
court had already concluded that Graves was subject to a
mandatory life sentence, he did not submit to a presentence
interview or file a sentencing memorandum in an effort to
obtain a lesser sentence because that effort would have been
futile." So, yep, a remand is the appropriate response.
Now, will Judge Sabraw give the defendant a life sentence once the case gets back to him? I'm quite confident he will. (At least if the recently-passed First Step Act doesn't apply.)
But going through the motions is an important part of the process. Particularly when you're making someone spend the rest of his life in prison.