The police responded to the first shooting, determining, I assume from interviews at the scene, that it was a domestic dispute. Apparently they didn't have any ID on the killer, and they assumed he was gone from campus. There was no indication that this person was going to go on a shooting rampage on campus.
The administration DID contact students through their RA's by telephone, and began a telephone tree to contact others. They also sent a blast e-mail to all students in the system, after having done the calling. The President said that there were sirens going off on campus as well. As the college President pointed out, many students had already left their dorm rooms for their first class, and by the time the major killing took place, some of those students may not have even known about the situation.
The gunman hadn't been killing students continually for two hours. If it was one gunman, he shot two earlier in the day, then either hid out on campus, or went back to wherever he lived to re-arm and come back. On a campus as large as VT, he probably could have gotten on campus from just about anywhere, even in a lockdown situation. I doubt the place is fenced in and gated, so folks come and go all the time. From what I've been able to gather, the second wave of shooting didn't last that long, so the administration would not have had time to react to that one, either.
If this was the case, during those two hours, why did they assume the shooter had left the campus? During the news conference one of those interviewed said they assumed the suspect had left the campus after the initial shooting. Do you know why they would assume this?
If the VA Tech admin's hasty response was suitable in this situation, why would the above fact be the case?
The real 'blood on their hands' moment is the quashing of the CCW bill at VA Tech.