Theft may see him in jail but failures cant and wont. IF we went that way if you made a mistake at work would you go "rot in jail" for it?
I agree with most of what you said but you are wrong about one thing - if you are in a very high position in a company like director or higher, you actually can be held responsible for failures due to incompetence/negligence. There is real precedent for this (at least in the US.) So yes, you could go to jail. I think there is a strong argument that Mark could be found both negligent and incompetent.