The first guy to get to the DA’s office gets the best deal. Look at Enron.
Ken Lay stopped taking his heart meds and died. Fastow who was the SFO and behind the entire mess was married into a family with major connections so he was safe - even though all the fake companies had names that, amazingly, were the same as his family members. So Skilling took it head on even though he didn’t even work for the company anymore.
And because he died before sentencing his guilty verdicts were expunged from the record also.
You bought the Ken Lay death story?