Ken Lay did not operate in a vacuum, his employees were in on the scam. They would scurry to fake trading rooms and act busy to impress investors.
The real tragedy in the Enron case is all of the employees did not get sent to jail. Hearing about the woes of former Enron workers, makes me want to barf.
No one who owned Enron stock complained while the scams were making them money; they only complained when the bubble burst and they did not reap the "rewards" they expected.