Correct, which is why the individual opinion has no bearing on whether something is objective, anything experienced by the individual is purely subjective, it is only with the agreeance of an outside impartial observer that anything can be determined as “real”.

So in the given example neither of their opinions are real without external context. We know from history that that context includes Jew’s trying to survive (defensive violence) and Nazi’s trying to kill them (offensive violence) and thus with this external impartial context we can determine that the morality of harm lies in favour of the Jew’s and that the Nazi’s are objectively morally incorrect.

Now for the mud. That can only be said of the cohesive group identities and their aligned moralities. To make the same determination for each individual person you need to understand their individual context.

The social consciousness understands, as you do, violence bad. But they lack the context and nuanced understanding that comes with asking more specific and just as important questions, which is something that you might have been able to pick up here.

Edit: Almost forgot the core point, going back to the original discussion, I think we can now agree that the morality of violence can be objectively determined with adequate context and removed from the opinions of the perpetrators. As such I believe we can most definitely devise a determinate system for the censorship of harm.