L1 drivers are not micromanaged to the extent that L2/L3 is and can continue to run a service without the control room.
I bet the 'shut down to install new equipment' was a switch that allows the transfer of control to Moore Park without shutting down Randwick control first - I'd bet the transfer can now be done remotely at the bunker.
I gather that fire alarm took so long to recover from was that when the alarm went off everyone quickly evacuated Randwick but forgot to 'transfer control' to Moore Park. So they OCC staff decamp to the bunker and find they can't log in. No one's allowed back in Randwick to 'transfer control' till the firies hand the site back.
Meanwhile, the 'micromanaged' L2/L3 grinds to a halt as the trams are no longer getting updates from the OCC traffic management system.
This isn't a unique problem - the Metro is totally dependent on its control room too - and several service interruptions have been caused by fire alarms causing evac of the OCC. The trains stop getting updates from the OCC and won't leave the next station. The on-train staff, while all trained in manual operation are not allowed to take over control with passengers on board and certainly not without direct instruction from the OCC (which is of course not issuing instructions as it's been evacuated!)
The problem is that the staff 'on the ground' are not empowered to make any decision what so ever. Every action has to be cleared by the OCC.