Comment by scarmig

The Junior dev does bear a small amount of blame, if you really want to go the blameful route.

But figuring out who to blame is toxic. You've got to go for a blameless culture and instead focus on post mortems and following new and better processes.

Things can absolutely always go to shit no matter where you work or how stupidly they went to shit. What differentiates good companies from bad ones is whether they try to maximize the learning from the incident or not.