The post in question was obviously loaded. The poster's comments were absolutely out of line with the community in question. There was nothing polite or civil about them and questioning why one wouldn't engage with uncivil discussion is at best ludicrous, at worst, toxic. They then got upset that they suffered consequences and got ragged on for it when they acted all hurt that their actions had consequences.

At no point was there any civil way to engage with the person. If you think they were civil, you have an odd baseline for that. Turning the other cheek isn't a requirement in society. No one needs to deal with toxic people of they don't want to. Honestly, with how hard you're trying and the communication between the two of you, I almost feel like you two are the same person. Like, what happened to the original poster is not mysterious to anyone but them.