. >> when you met her and heard about liz beth holmes vision what did you think?was totally sold on it. >> reporter: tyler schultz began working at the company in september 2013. a pivotal moment, as the company announced a partnership with walgreen's. the deal would put an edison machine in every store. elizabeth holmes claimed the edison performed all of the tests big lab machines like these could. from cholesterol to cancer. all from a painless finger rick. but tyler schultz says the edison he saw just didn't work. >> was it a sophisticated piece of machinery? >> no. come components would fall off in testing. you had to fish out. doors that wouldn't close. they would get too hot. get too cold. >> when i was there we could not complete any test accurately on the devices that we were manufacturing. >> reporter: doug mechie joined theranos in 2012. his job was to adapt blood tests for the edison. tests which holmes told investors were ready to use on patients. >> but liz beth holmes told walgreen's in 2010 it developed a device capable of running any blood tests f