My opinion is that this is a mistake on their behalf for poor planning -- it is not a routine hardware failure which we all accept can occur from time to time but still should be minimised through redundancy.
from the PR release above it seems they do have redundancy, but that is what is causing the problem :)
When the AKL server crashed due to an upgrade ( yesterdays AM outage) it become out of sync with the CHC server. Then when they tried to restore the redundancy ( so everyone was not trying to use the same server) overload occurred and the CHC server had to be taken offline.
With out the redundancy I would say that there would have been no internet for Telecom users at all yesterday AM :)
edit: fixed grammar and spelling, need coffee :)