Not everyone experiences conscience in the same way. He might not even have one to torment him in his moments of solitude. And when you say "mildly unpleasant

Not everyone experiences conscience in the same way. He might not even have one to torment him in his moments of solitude. And when you say "mildly unpleasant", I can only assume you mean that for the rest of his life, his sole source of genuine unpleasantness will be from his own psyche. Because he'll be worth a billion dollars. And while money can't buy happiness, it can remove every last speck of annoyance, peeve, and inferior market option. This failure will be easier for him than for most other people who fail far less spectacularly. Even if a thousand people make it their life's mission to persecute him at every moment of the day, he still has approximately a billion dollars more than all of them put together. All he really has to worry about is avoiding Saudi-controlled buildings and territories for the rest of his life.