Yet it is hard to believe scientists would be the ones who only ship flawless software. And easier to imagine that most often, when one realises a previous publication's result was indeed impacted by an error and faces the difficult decision to retract or pretend they haven't noticed, they opt for the other route. I've found scientists in general to have less ego then average, as expected from people trained to care only for the facts, but they still operate in the larger framework of individualistic modern society. It probably takes a scientist and a woman, whose education generally encourage lesser ego to begin with, to admit such an error.
Or a software author, but there there is no other alternative to guilt admittance than total ridicule, since we are drowning everyday in a world of errors.