Cost-benefit analysis: spend a few hours trying to translate a raw flash dump into a readable format (in addition to the normal forensic work of looking at the phone's drive's contents), or spend <1hr to see whether a pro forma subpoena makes all that work unneccessary?

This isn't a high-priority case, so the FBI will always go with the cheaper, quicker option.

Good grief: "mount -o loop raw_flash_dump /where/ever". I weep for the state of things that straightforward tasks like this seem "hard" not just to yahoos at the FBI but even to Javascript jockeys who frankly should know better.

Going to court harder than spending half an hour to dump the phone? Really?