That's exactly why I ask clarifying questions.

Bad faith arguers usually won't answer a question because then they'd have to reveal they're arguing in bad faith. But that ends up being the tell anyway.

There was a recent instance where I asked someone if they really supported free speech, which they arguing for in response to a Canadian policy that would criminalize calling for genocide. Really supporting free speech meant permitting calls for genocide against a group that included them.

They never answeres the question about whether they supported calls for genocide that might include them. I asked them twice.

In that case, it's easy enough to just stop responding to anything they say. They've outed themselves by not participating in the conversation.