"“If you're standing there in that skirmish line, and somebody's throwing something at you, is it really up to you to be figuring out whether it's gasoline or whether it's metal, or whether it's water or whether it's acid?”"
His use of military terminology ("skirmish line") is telling.
The terrible (and currently true) idea that the police are exempt from assault and battery laws is so widespread that people don’t seem to notice how biased they are. The police need to be held to a higher standard, as public servants, but the first step is just holding them to the same laws as everyone else that say you don’t get to arbitrarily pepper spray or beat anyone you feel like.
Contempt of cop is not a crime, and cops retaliating violently should be tossed in the same hellish system they force others into for breaking the law. There is no equal protection in practice so long as one group can attack and harm anyone they wish under the guise of their job title.
They’re already entirely exempt from gun controls that apply to the rest of society; if they aren’t restrained from illegal activity by legal process, then the situation is indistinguishable on a practical level from military dictatorship.
'Skirmish line', to my knowledge, has no accepted non-military uses, but even if it did the interviewee is clearly referring to the military formation and therefore considering the protesters to be hostile enemies.