That's where you and Gorman disagree. His point is that, yes, people screwed up; but no, they didn't do it deliberately. We don't throw people in jail for being bad at their jobs; we throw people in jail for deciding to do something wrong.
If an engineer signs off on design work which then fails and injures/kills someone due to their incompetence they can and are charged with professional negligence and sent to jail.
Although financial incompetence doesn't kill anyone, it does effect a much much larger number of people, so I don't see why we shouldn't take the same approach and make the directors of financial firms personally liable for the outcomes of their actions.
And medical misconduct and malpractice often involve federal investigations, that tells you it's not considered trivial.
Yes, it is hard to say but no, you cannot behave unjustly even if other people want you to. You cannot get a slave even if the other person wants you to get him as a slave. You cannot harm an inocent person even if he wants you to.
The problem with Lehman was, essentially, that of lack of responsibility. And this is inherently unjust.
So: with the letter of the law, they "do not need to go to jail" (say Lehman's board of directors), but with a reasonable understanding of justice, they acted in an unjust way. Wittingly.
If you claim that an individual was just doing their job, their superior should be held responsible for creating that job (up to and particularly including the CEO).