Testimony would indicate they (Huber, Grosskreutz) didn’t have a clear idea why they were chasing him and certainly not firsthand knowledge of the events between Rosenbaum and Rittenhouse.
Somewhat ironically the claims about Rittenhouse causing provocation merely by carrying a rifle openly would have been alleviated if he’d been legally allowed to carry a handgun instead.
They made a mistake. They shouldn’t have chased and attacked someone just because the general consensus of the mob was ‘get him!’ Kind of the same way the McMichael’s shouldn’t have chased Arbery without any firsthand knowledge of events. That Rittenhouse was acquitted and the McMichael’s were found guilty is evidence that these two juries judged these separate events in a similar way.