It's a fine line, Dober, and as individual as the dog.
When Cleo air snapped at me when I was transporting her, if I had let her get by with it and hadn't turned right around and told her I wasn't putting up with that kind of nonsense I'd never have been able to do anything with her. BUT -- after I did that, I let her know we were okay, because once she chilled back out in the seat behind me in the truck (cab and a half, talk about tight quarters with a strange Fila, lol!), even though she was still wary, I went back to opening the SlimJim, talking to her the whole time in a normal voice, and gave it to her, not all at once, but she had to eat it a small piece at a time from my hands, letting her know that she was going to have to trust me, but showing her that I was going to trust her in return.
Sometimes you have to get the message across that snarkiness just will not fly.
It was a calculated risk in that case, but if I had let her get by with it I don't think I'd have been able to work with her, or at least not without more drama. I had to BELIEVE that I was in control of the situation strongly enough that Cleo believed it too, but without playing that silly-assed dominance bullshit. We established a base line of mutual trust and respect that we could work forward from.