So, it's not a terrorist act because? The police, the media, together with ISIS want it to be, and the guy just happens to be muslim, doing what others do on saturday nights and he rolls on the floor in an incorrect manner.
What would or wouldn't make this fit into the current narrative of terrorist attacks is not how this man rolled on the ground, nor is it even his low budget attack or an unsubstantiated claim that he is raving mad, but his "motive", which he clearly stated.
It is wishful thinking on your part that makes you try to shift the narrative away in denial of the facts. I would guess this is due to your legitamte fear of the broader consequences, ie; the effect these attacks have on shifting political perceptions and a rise in intolerance towards normal muslims.
This guy had a knife, the last ones in London had a knife and a car, the one on the beach in tunisia had a kalishnikov. All had the same motives.