You, because the moment you leave you become that-guy-who-we-can-safely-blame.

Mostly joking but plenty of places do work like that.

Yes, they'll blame him. It won't make sense for the most part, but it'll still happen. Probably largely things like "it only tomelders had worked with us more instead of being 'difficult', we wouldn't be in this mess", even if the 'mess' is precisely what he was advocating people work on before he left...

I will always blame whoever most recently left for everything. The rain, the chair being broken, the mouldy cream cheese in the fridge.

No jokes. It's Brads fault.

It will indeed be his fault. He set them up for failure and left, they'll say.

Isn't there a name for this pattern?

I swear I remember reading a piece on how having a team member leave can be good for cohesion and efficiency, because everyone is free to vent about old, bad decisions without targeting anyone still at the company. I think it was part of a story about a team clearing their technical debt by convincing a reluctant manager that they needed to undo the last guy's mistakes.

"Blame Canada". PM: "We can't blame Canada for missing our targets 4 sprints in a row."

And in a way it's saner than if you blamed over and over some people who still work 5m from you, even if they deserve it; and we all have stories about that kind of people.

You often needs to be more subtile with them (x) than blatantly calling on their bullshit every time...

(x): I mean to try to influence them so they progress so your life is better, not to shit on them