I've been a professional System/network admin since the mid-1990's. I'm very familiar with IT incompetence in large organizations.
I doubt they're sharing all the details, but yes it makes sense. It was a very avoidable, but completely realistic issue. I don't think the average Internet use has any idea how tenuous everything is. IT departments never get the funding they need, and the larger the organization, the more incompetent people they have.
I just recently moved our companies data center, which involved making BGP changes. Cisco gear (IOS) has commands such as "reload in #", which will do an automatic router (switch, firewall, etc) reboot if the reload isn't stopped. This is a great way to reset the router to last known good config if what you enter cuts you off or does something else you're not expecting. Higher end Cisco routers have even more config management that allow automatic rollback of config commands if you don't perform some action (commit the config, etc). Most other router brands have a similar thing.
And that's just one example of how to easily avoid a multi-hour outage. The first would be to make sure the config you're entering is actually correct!
So no conspiracy. Just incompetence. This isn't even unheard of. Incorrect BGP config happens quite often. It just doesn't always hit the news like a Facebook outage.