>They refused to let me fix it, not because we didn't have time (there was plenty, and I was otherwise free to work on pretty much whatever was in the backlog), but because fixing the bug would let the customers know that there was a bug in the first place. Some of this data would end up getting passed on to shareholders and the government. Is this not a bug?

No, it's an opportunity to ask for a large sum of money, to leave the company and not talk about it.