Earlier quoted context omitted.
I think you misunderstand. Even with code review policies, there is still a short list of people who can push to production without going through code review. Not from a policy standpoint but from a security and access perspective.
The chain we had in ${BIGCORP}: Programmers: read-write to repository Staging team: read-only on repository, read-write to test servers and staging zone Deployment team: read-only on repository and staging zone, read-write to production It wouldn't prevent malicious code going out but at least would require a chain of cooperation between employees, which would be harder to achieve.
No, it just requires a chain of cooperation between authorized accounts. That's a very important distinction, especially here, where the email in question alleged the following:
This included making direct code changes to the Tesla Manufacturing Operating System under false usernames