tyler schultz. but tyler wasn't just a theranos employee. he was also the grandson of one of the company's most influential board members. george schultz, the former secretary of state who was also a long-time mentor to elizabeth holmes. >> good morning, mr. schultz. >> good morning. >> reporter: what tyler would reveal was ultimately the story he would tell under oath in this deposition years later. >> can you recall any of the factually not true things that ms. holmes told you? >> the big ones are being able to run hundreds of blood tests from a single drop of blood. my grandfather would go and get a theranos test done and he would have a needle in his arm. you know, it's like, i thought it was a single drop of blood? and there would be some excuse about why they needed to take aa venous draw from him, but from everybody else it's a finger prick. when you read it, it sounds like the tests were being run in walgreen's, but most were sent to theranos on third party machines. >> did elizabeth holmes know that the that machine could not do all