(IIRC, Holmes' lawyers also made the argument that it was not legally possible for her to have committed wire fraud against the patients, because any money that Theranos received would have come from their insurance companies.)
Part of the difficulty is that the empirical data that would have proven how well (or poorly) the technology worked was allegedly stored in a proprietary, bespoke database. When Theranos was ordered to turn over the data to the feds for discovery, they delivered an encrypted copy, and then claimed that the encryption key was lost and the original disk arrays were unrecoverable. Both sides of the case then blamed each other for destroying the last remaining copy of the data, which made for some fun reading.
Here's one report on an invalid pregnancy test:
https://www.theverge.com/2021/9/21/22687026/theranos-patient...
They decided that she had.
FWIW, every single firm that had medical expertise declined to invest in Theranos. They could see it had extremely minimal chance of success.
This doesn't hold with what was found in the trial. She was found not guilty on those counts. Just because a dude wrote it down in a book doesn't mean it's true. And the legal process found it to be, in fact, not true.
The jury didn't find that the results given to the patients were accurate. They found that Holmes was not personally, criminally culpable for wire fraud in those cases. Wire fraud is a crime that has very specific elements, well beyond the question of how accurate the test results were.