Seems like you're still assigning blame. Incidents are rarely if ever monocausal. The fantastic and accurate point the GP made is that fingerpointing is pointless. Much better to seek to learn and understand, which is always difficult but definitely can't be done from the sidelines without speaking to those involved.
Some people have an important role to play when other people mess up. The fire brigade aren't the ones who start fires but it's their job to try to help out when it happens. If they don't show up when your town catches fire, you would be disappointed.
Can't blame support for something an engineer did.