No, I said that closing the campus would not have prevented any more deaths, meaning that people still would/could have been shot.
If the campus had been closed by 9 AM (that's 90 minutes to do it!), there would have been ZERO classrooms for that kid to use to kill trapped people.
He *could* have done anything in the open field of a campus filled with cops chasing people out. But look at this:
Would he have shot 50 and killed 32 in a campus where kids had been told to leave for the last 90 minutes?
Would he have shot 50 and killed 32 in a campus where kids knew about the shooting?
Would he have shot 50 and killed 32 in a campus where kids had a chance to run/duck/roll/sprint away outdoors?
If those buildings had been locked, those kids never would have entered that fish-in-a-barrel situation and deaths would have been less, and security would have had OUTDOOR access to kill the kid before he had 30 minutes of roaming kill time.