Maybe, maybe not. Until there is a time line of events we won't know.
I could walk into a croweded room, fire 23 rounds( thats 3 reloades) from a 1911 and blow my brains out with the last one in well under 20 seconds.
At best some one might be able to respond in what 5 seconds? thats still atleast 8 shots off.
The cold hard truth is, if some one wants to kill people and is willing to give up thier life to do it,its extremely hard to stop them.
Even the highly skilled pros have a hard time doing it.