It’s not in any way a justification. In fact the language is deliberately neutral as not to imply the protestors did anything wrong (which they didn’t) a protest happened and a cop was shot. Just stating objective fact, because that is a crucial detail the the other commentary left out, which makes their comment sound like they arrested and sentenced these people purely for protesting. (Which they kind of did, and the cop being shot was just their justification, but that’s besides the point)