Uh. You are wrong. The floor and medial wall of the orbit is paper thin ( lamina papyracea in Latin). That’s what breaks in an orbital floor blowout fracture. The only way it might be fatal is if you got an infection that tracked into the CNS.
Now any blow to the head, in the right circumstance could lead to an intracranial hemorrhage. But that’s not directly associated with an orbital blow out fx.
Gents, I'm not really sure what point this is about. If someone or something hits you hard enough there to break the bone, you have been hit very hard indeed. That event can kill you. In practical terms, the cheekbone is massive, the brow is massive, and if someone has managed to break into that shark cage and break the orbital, you're in big trouble for a lot of reasons. It doesn't matter if your death is directly associated with the orbital break or not. The concussion you may get from the blow itself could be enough to kill you; the force to the back of your head if you fall down could be enough.
Meanwhile, the very fact that something between the fist and your brain is breaking and thereby absorbing shock could actually reduce the force reaching your brain case. But even so, it's often not enough, because people often die from these events. The knock-out "game" comes to mind.