Once again, you show all the sensitivity of a blunt axe.

I would rather die than betray his trust."
"That's not saying much, seeing as you're already dead," Ron observed.
"Once again, you show all the sensitivity of a blunt axe," said Nearly Headless Nick in affronted tones.

But you would think, wouldn't you, that getting hit forty-five times in the neck with a blunt axe would qualify you to join the Headless Hunt? - Sir Nicholas de Mimsy

You," Madeline said, her voice hollow and wheezing, "are like a bad case of herpes, wizard. You're inconvenient, embarassing, no real threat, and you simply will not go away.

He uses statistics as a drunken man uses lamp-posts... for support rather than illumination.

The man is as useless as nipples on a breastplate.