SAN JOSE, CALIF. – Elizabeth Holmes was the founder and face of Theranos, but when it came to the company’s laboratory, she relied on her highly qualified lab directors and scientists.

This is the image her defense lawyers painted Wednesday to try and discredit Erika Cheung’s testimony, a whistleblower who was a former Theranos laboratory associate. She claimed that Edison blood-testing machines often failed quality control tests.

Lance Wade was a defense lawyer for Holmes. He reviewed the qualifications of Theranos scientists, including “52 scientists with PhDs” and “10 medical doctors.”

Cheung, wearing a gray and black dress and heels, spent six hours in the witness stand, describing the Edison’s high failure rate, data manipulation, and how it affected the Edison mini-blood-lab machine.

Cheung explained that “you’d have approximately the same luck flipping one coin, regardless of whether your results came out right or wrong.” It was alarming to witness this level of failure. This was unusual for any normal laboratory.

Cheung worked for Theranos less than one year. She said that her lab managers were Adam Rosendorff (a doctoral student) and Mark Pandori (a scientist with a PhD). Cheung quit Theranos and became an advocate of ethics in tech. She founded a non-profit, Ethics in Entrepreneurship, with Tyler Shultz, her ex-colleague, who was a whistleblower.

Holmes arrived at court wearing a dark green gown and matching mask. She was joined by her mother Noel Holmes who attended all hearings since last week.

Holmes was seen hugging her mother during one break. She has pleaded guilty to 12 counts of wire fraud. 

Wade presented Cheung with several validation reports regarding the assays she had testified to be problematic during cross-examination. He pointed out that the lab director and vice-president signed the validation reports for the lab tests. Holmes didn’t sign the document.

Cheung said that lab quality controls would often fail, so Cheung explained that company used an “outlier delete” system to pick the highest-quality data points. Cheung confirmed later that quality control testing were not performed on blood samples from human subjects.

Cheung also testified earlier in the day that many lab workers manipulated data in order to make the devices work. According to her, she brought her concerns up to Ramesh Balwani (Hammer’s second-in command and at one point her romance partner).

“I received a positive response from him. Cheung said that you have no visibility within this company.

Balwani has also pleaded innocent.

Cheung said that she raised her concerns to Shultz, his grandfather George Shultz (ex-Secretary of State) and Theranos Board member George Shultz.

Cheung stated that it was becoming very difficult and stressful to be employed at the company. “I tried telling as many people as possible but it wasn’t getting across to them.

Cheung will testify on Friday.