The most charitable interpretation of that remark is, We don't think it's part of a larger conspiracy.
Certainly, on the face of it, it's a textbook example of Sudden Jihad Syndrome.
It WAS in fact a terrorist event, in the way AT THE VERY LEAST , that any act of multiple murders and massacres are terrorist events, politically, or religiously inspired , or not. Hasan should’ve been taken seriously when he started talking about these things, and there were more than a few people who heard him say them, and ignored them. We never learn. Think there will be a review of how we might avert these acts of murderous aggression in the future? I don’t think so. The Virginia Tech murderer also paved his way with lots of warning signs that were overlooked, or dismissed. Everyone in ‘authority’ is afraid to act pre-emptively, so they basically wind up dying. Or, should I say, WE wind up dying!