"They" refers to the pilots. And, while a complicated technical problem is likely to not be the pilot's fault, after a certain degree of refusing to cooperate

"They" refers to the pilots. And, while a complicated technical problem is likely to not be the pilot's fault, after a certain degree of refusing to cooperate with the investigation, it becomes their fault. Also, onemileatatime is a long-standing news website that reports on the aviation industry; the NTSB "released their side of the story" in press releases.