1. Day-to-day variations of platelet and red blood cell count/volume in the range that you describe is possible. Although it may be highly unlikely, a single personal experience based on two blood sample collected on two different days is not enough to cast much doubt.
  2. Experts who guessed (correctly) that the Theranos claims are impossible to realize may be reluctant to speak up until after they have enough data to backup their skepticism. This left a time-gap during which susceptible investors were duped.
  3. Theranos story is hardly unique. It is just one example of the “vaporware business” practice. There are many other examples to be found that follow the same playbook — some projects on Kickstarter even claim features that violate one or more laws of physics, but still they get funded.
  4. Preventing this kind of inefficiency in investing / resource allocation may be possible if investors more openly share their assessments with each other. For example, when Google Ventures turned down opportunity to invest in Theranos, their reasons for rejection, if openly shared with other investors, could have warned other investors (and ultimately benefited society).
  5. On the other hand, Google Ventures is likely to view their due diligence reports as competitive advantage, relative to other funds. After all, Google Ventures chose to invest in hiring the right experts to evaluate opportunities like Theranos. Why should Google Ventures let other funds get a free ride?