If, in fact, he felt he was firing to stop a shooting in progress, that’s hardly “attempted murder”.
Why would he feel that there was an 'active shooter' at all? He knew several things about the actions of Kyle Rittenhouse, as he was proceeding along the street from the CarSource lot after the shooting of Joseph Rosenbaum.
1. He understood the crowd was shouting 'cranium him' -- which he understood indicated 'kill him' -- this meant that Kyle was in danger from the mob, unquestionably.
2. He literally approached right alongside Kyle for an on-camera live stream video and thus discovered he was heading for the police line at the corner, not too much farther along north on Sheridan Road.
3. He saw a guy knock Kyle in the head with a cement chunk/large rock, and then Huber came in to strike him with a skateboard (the first time), and Kyle fell to the ground.
4. He witnessed Maurice Freeland kick him in the head with a flying jump karate move.
It was at that point when Kyle opened fire in self-defense.
5. Huber had by this time retrieved the skateboard (which had flown out out of his hands during his first attack), and Huber resumed his aggression against the now-on-the-ground Kyle, striking a blow to his head, while simultaneously grabbing the weapon.
Gaige saw all of this happen, and then --
6. Another individual (never identified) was in close proximity and stopped his advance, raised his hands and Kyle did not shoot him. That individual backed away, while Gaige proceeded to come in closer, a Glock in his right hand.
7. Gaige likely thought the rifle had jammed/malfunctioned and was inoperative (he was correct, actually -- the weapon did jam after the shot into Huber's chest). Unfortunately for Gaige, he hesitated a moment, trying to get right up alongside Kyle for a head-shot.
That allowed Kyle to hit the forward-assist button on his AR15 and seat the cartridge in the chamber. That action probably saved his life.
All of this is on videos.