Somebody fired in the air, at an angle, as Rittenhouse is getting chased across the parking lot. That's obvious from the video. Kyle seems to have had his back turned to the shooter, as he was fleeing, but I'm sure he would have heard the gunfire, and may have considered that he was being shot at. Things happened pretty fast when Rittenhouse and Rosenbaum entered the parking lot, but there were several shots fired, with one obvious in the video footage before Rittenhouse turned and confronted Rosenbaum. There were obviously other shots fired after Rosenbaum went down that seemed pretty close to the scene of the first shooting.
