Well, you're right in the sense that Rittenhouse "provoked" the crowd by putting out the fires that they were setting.
But the second part of your claim doesn't make any sense. If Rittenhouse's motive in provoking the crowd by putting out the fires they were setting was having an excuse to defend himself, why didn't he at first? If the point of putting out the fires wasn't to protect the town, but to have an excuse to shoot people, why was his first reaction to the ambush to run away towards the police line? If he wanted to shoot people, why run away and try to get to safety and only defend himself when he was cut off and knocked to the ground? Why not defend himself in the first place and not wait until he was literally seconds from being killed?
A few points of order, cmikes.
1. Rittenhouse was not engaged in putting out any fires, prior to him grabbing a fire extinguisher from someone at Ultimate location and going down Sheridan Road to deal with the increasingly volatile situation at CarSource3 (where he was then ambushed by the Ziminski couple -- 'Bonnie & Clyde' -- and Rosenbaum)
2. Immediately upon facing the armed Ziminski, his first reaction was to set down/drop that fire extinguisher and get both hands on his rifle. Rosenbaum suddenly appeared from behind parked cars, and Kyle ran away from these threatening actors, racing across the parking lot (not towards the police lines) with Rosenbaum in hot pursuit (and throwing the bag) while Ziminski opened fire with his own gun.
3. After Rosenbaum was neutralized, Kyle stopped for a few seconds to review the scene, quickly called Black to say he had shot someone -- "I had no choice" and then within that commotion (including more gunshots echoing) he started to move quickly northbound up Sheridan Road, towards the police Bearcats at the Ultimate location at 60th street.
4. It was during this run that he was struck in the head by a chunk of rock (his hat flew off); hit by Huber's skateboard the first time; attacked by Maurice Freeland's flying kick; sliced in the neck/shoulder by Huber's second attempt at 'cranium-ing" him; and then having Grosskreutz come right up to him with a drawn handgun.
Let us remember one thing, there was an individual right alongside Grosskreutz, who initially was moving towards the prone/sitting Rittenhouse, and he backed off, and thus no shots were fired at him.