Since they are testers and not auditors, what prevents Donut Labs from changing the actual battery sent for testing, selecting whatever works best for that specific test? In aggregate each test would seemingly validate their claims, only nobody ever validated and audited the fact that the same exact battery was used in all the tests.
As many have said, so many red flags around something so exceptionally revolutionary that you'd need extremely strong and unquestionably real proof.
Nothing prevents that, and the test lab wouldn't bat an eye at that. For all they know or care, you wanted to run different test on different cells. The only thing the lab is verifying is that the defined test was executed as stated, nothing else.
Nothing, that's why this comes off as largely performative and awfully suspect.
Let me put it this way - these labs are functionally pretty similar to a Qwest diagnostics or Lab Corp. Those places draw your blood and run tests on it. The prescription tells them the tests to do, and the doctor is the one who evaluates the results. The labs are just a dumb tool to do the testing as prescribed.
Donut in this case is writing their own prescription and then posting the results. Just like a lab, they don't interrogate you to see if you are manipulating your blood results. That's the doctor's job. And ultimately at the lab it's just a lowly tech going through the same motions they go through every day.