Propper security I depth means that when trusted actors betray the system, the damage is limited.
Like, consider your personal cult was built around an "unopenable" bolt-tighted box. Then someone invents the wrench in an attempt to open it. That would be a clear "security vulnerability", right?
Modern security is defense in depth. The AI pre-prompting setup was the first layer, and it was escaped. The UID separation inside the container was another, and it was broken. The container would have been next. And hopefully there are network firewalls and egress rules on top of that, etc... And all of those can and have failed in the past.