For what it's worth, revenge doesn't require a net benefit to the situation. The word "revenge" is kind of similar to "retaliation" where an actor is purely seeking retribution for a past event without regard.
To us, it's not justifiable. Hell, the ex-admin may think so too. But that doesn't mean we should automatically side with the employer and subsequently crucify the ex-admin. We don't have any information yet.
How do we even know the story is at all truthful? Maybe someone who still works there did something stupid they couldn't recover from and is now blaming it on "an ex-admin" to make it sound nice.
Is your first assumption that people only post their first assumptions? WTF dude. There are plenty of people in this thread already ready to tar and feather a completely unknown person. I'm just trying to point out that we don't actually know anything about what is going on.