The Wall Street Journal, and in particular, reporter John Carreyrou, deserve a special callout for launching an investigation while the rest of the press was idle. I was struck by this ProPublica podcast with Carreyrou in which the interviewer, a Pulitzer Prize winner himself, said he and other health reporters had heard grumblings and rumors but don't enough to pursue a closer look. Carreyrou, on the other hand, said he acted on a New Yorker profile (which, IMHO, was fairly well balanced) in which he was curious how the company could keep its technology so obscured.

https://www.propublica.org/podcast/item/how-a-reporter-pierc...

http://www.newyorker.com/magazine/2014/12/15/blood-simpler