What I find interesting about the way they're talking about the shooting is that although "more could have been done," the former Secret Service agent seems alright admitting that it wouldn't be practical.
After the Kennedy shooting, after the Reagan shooting, after the Giffords shooting, the question is raised, "Could we do more?" But where Politicians are involved, we also ask, "Should we do more?"
Not the same way we respond to other national security incidents.