But are there clear rules of what kind of "help" you can and cannot provide? None of the individuals harmed while attacking the gunman needed to intervene either - and I'm sceptical they all had first-hand knowledge of the 1st shooting versus hearing the allegations of the crowd/mob.
Reminds me of https://en.wikipedia.org/wiki/Xu_Shoulan_v._Peng_Yu - same ethic of "if it wasn't his property, he must have been looking for trouble"; If that's the case every out-of-town protest/rioter is also an instigator.
Truth is, we don't know what preceded Rosenbaum chasing Rittenhouse, and until we do, we don't know who threw the first punch.
> The police are there to deal with it
last I heard the US police have no duty to protect. Until this is changed, people will be in no hurry to surrender the right to bear arms.