Not a big fan of the wording here. Plenty of skilled programmers make dumb mistakes. There should always be systems in place to ensure these dumb mistakes don't make it to production. Especially when related to sensitive information. Where was the threat model and the system in place to enforce it? The idea that these problems are caused by "shit programmers" misses the real issue: there was either no system or an insufficient system to test features and define security requirements.