The Holocaust survivor who was killed, was a hero. He put himself against the door, while his students jumped out the window.
Was the holocaust survivor the same as the Romanian professor - same person? Yes, he was a hero to block that door. But the shooter did target that room, that class. He went shooting on the 2nd floor of the building, not the first floor not the third floor. No doubt the shooter would have known (as a student) when and where this Professor had a class.
Just speculating. Just seems like this was a targeted shooting not just an aimless rampage done by someone with perhaps military training.
God bless the Professor who blocked the door.