Break glass systems are very good but they are also challenging to make. It requires at minimum a system to get approvals from n other people and a system to do logging. It means your authentication and authorization systems must both be working, at least a small amount of non-volatile storage is available, and this often implies the availability of more foundational services such as service discovery, name lookup, distributed consensus, and replicated storage.

The problems can be overcome, but management types may balk at the cost of a complete break glass system.

In your scenario anyone who had $1B or more before midnight is now $1B poorer, so I don't think people would be very happy with that engineer either, regardless of whether there's a break glass system.