If only they would use the full capabilities of the equipment.
The Citadis are fitted with traction batteries and apparently have 500m
or so of 'range' under battery power.
The concept drawings for the electrical network show that each section
can be feed from the adjacent one, so no single substation failure
should take the system down.
Between batteries to work past a damaged bit of overhead (or blown APS
section - the reason why Alston fitted the batteries!) and the cross
feed capability, they should be able to keep things moving instead
throwing hands up and calling in the buses. Then deal with the actual
fault quietly in the background or later when things are quieter.
The Metro has suffered from this a few times too - a train breaks down.
It happens. But instead of running a limited service using the
bidirectional signaling to work around the failure they shut down and
call out the buses.
Looks like the engineers build in all sorts of contingencies for
degraded operation, when then gets wasted as the operations management
people appear to be too scared to use it.