Like many people higher up, he'd made large bets and instead of admitting he'd screwed up, he tries to keep the lie going. This is extremely common behaviour,

Like many people higher up, he'd made large bets and instead of admitting he'd screwed up, he tries to keep the lie going. This is extremely common behaviour, high up and on the street, and it rarely benefits the person doing it - except in the extreme short term. There is something people don't realize about decision making : time horizons. You make decisions that benefit you in time. That means you consider whether an action benefits you at point X in the future. There are extreme examples, like giving a kid all the candy he'll get for a week and letting him divide it up. On the other end of the spectrum we have the Sagrada Familia. The people voting to have it built would never see any part of it. Their grandchildren wouldn't see more than a tiny bit. Their grandchildren's grandchildren would not see it. And so on. Now these aren't "pure" examples. The kid is not going to eat all the candy right then and there, and building the Sagrada Familia had economic advantages when it was being built, and even today. But if you consider most crimes at a time horizon of a day or two. They make sense, suddenly they become rational actions. HSBC and Jamie Dimon made decisions that would benefit them for years at least, and then lead to disaster. This is in fact quite a long time horizon. These are rational actions. Given the outcome, they are very rational actions.