Thats a good argument in a vacuum. But the world has determined "I was just following orders" is not a good defense.
We know the crimes against humanity are bad and subordinates are guilty if they do them. We don;t just let everyone off free except the head of state.
Not to see that united healtcare (as bad as they are) are anywhere near that, but I am saying that its clear that we, as a society, already hold all people complicit in evil as guilty. Not just the person at the top.