Agreed. I wonder to what degree it was just that they weren't prepared for something like that to happen. They've had streakers, political speeches, Oscars refused, Best Picture awards to the wrong film ... but I don't think something like this was anticipated. So they really didn't know what to do. Especially as Smith was favored to win.
One thing, perhaps a small one, is that it was too easy for Smith to reach Rock. If he had to walk along an aisle, then up steps to a stage, as in years past, I don't think he would have tried to do what he did.