I haven't been able to get a clear answer to my question about Theranos: Was what she offered obviously impossible? That's my understanding. Blood is not homogeneous so it is physically impossible to get an accurate full blood panel from a single drop. Was there every any plan to address this or was it clearly a 100% fictitious product from the get-go? Did any journalist ever ask her or any scientist at Theranos about this problem? If not, then what were the scientists at Theranos doing all day? Were they all in on the scam? Or were there no scientists?

I just don't get how you can spend years pretending to build something so obviously impossible.

Yes it is obviously impossible, as anyone familiar with the subject could (and did) say. You can't detect something that is so dilute that there isn't even a single molecule of it in a single drop of blood drawn from a capillary.

My understanding from articles, they had scientists hard at work trying to get their machine to work and the issues that were essentially maintenance (you really couldn’t have a testing machine like this that didn’t require expensive / regular maintenance as promised). The amount of blood wasn’t really even addressed yet and they faked results in house using competitors machines.

In house teams were not optimistic, but they got paid to experiment and try so they did.

I believe I read something about this film featuring a moment where Nathan insists that since she's innocent that they must go to the back yard to confirm how this machine works. Or something along those lines - in any case the absurdity of "I totally believe you, let me help you prove them wrong".

What I'm reminded of is that documentary The Jinx which basically takes you along for the ride until the subject accidentally confesses. Documentary filmmaking is so weird - there is always the element of fiction and make believe that somehow manages to get at the truth

A mix of needing a paycheck, "fake it till you make it" and psychopathy.