And if said software screws up and costs a few hundred million, or otherwise causes other "bad things" to happen, what's the accountability of the programmer or the manager?
Nothing. CEO's wreck companies/cause damages all the time, and all that happens to them, personally/financially is NOTHING. Maybe they get fired and then receive a nice golden parachute. Why should it be any different for the programmers who are the architects of the entire groundwork allowing the company to exist in the first place?