Interesting question. Funnily enough, i‘ve been asking myself about bad faith arguments a lot since the last couple of days. Seems like lemmy is getting run over again.
I personally dont immediately detect bad faith arguments so I always treat them like normal arguments. People then often get really annoyed at me, probably because they wanted me to be outraged or shocked. Then they lose it which really amuses me.
Calling out if I detect something like it has also helped. „So you are saying a group of people deserves to be abused and ultimately killed?“ to stay with satre‘s example.