It would depend (in this case) on tone of voice as much as anything. I wouldn't take it as a back-handed compliment so much as a grudging admission that whoever it was addressed to had a point. You're not as daft as you look, are you? Please Register or Log in to view the hidden image!
Yes. He's stating that whoever he's addressing generally doesn't ask good questions. What's the difference?
Usually a backhanded compliment requires a sort of mental double-take to understand the intended insult. The addition of the words "for once" removed that necessity and, to me, made it more obvious as an insult than a genuine backhanded compliment.
so a true backhanded compliment would be along the lines of: wow, that dress really makes your butt look small.
