It could be designed that doing so will generate some alarm to other people. For example, the backdoor do not exists and it has to be developed, so the attacker has to keep them hostage for some period of time and loved ones may report a missing person. The software then might have to be signed with a key that generate alert to the whole engineering team, which someone else in the company may investigate the unauthorized release as cyberattack. Perhaps the release signing key is physically stored in the office (eg. Yubikey) which also require the attacker to perform a heist in the office.

Surely some three letters organization probably could pull that off, but it add risk to their operation that the operation could be leaked.