This is the way it always happens.
The actual failure (finger trouble) should have had no effect. BUT
The failover data centre was too small, possibly from inception or because nobody had thought to check the growth against backup. This is an IT management failure of testing and continual monitoring.
The SAN being out of date is again an IT management failure as the continued maintenance and support of special equipment that supports the business should be part of normal IT management checks.
The other management failure shown by both of these is the failure to set flags that 'when the system gets this big' or 'when the system gets this old' a new system will be needed. Those flags should have been set on acceptance of the system and a draft contingency plan for how to replace the system should have been written and maintained.
With a cost cutting management it can prove very difficult to persuade them that the IT system which is still humming along, will need replacing in 18 months time and as the draft replacement plan says it will take 15 months to replace work needs to be paid for now to initiate contracts for replacement.