[c0balt]

If I have you hammer with a wax coated handle then it will regularly slip out of your hand.

One could blame the user for not "just" holding it right. Or alternatively reconsider if the handle should have a grippy coating instead.

[consp]

More modern version: No you are holding your iPhone wrong, it is not a design fault that makes a ground loop in the antenna if you hold two metal surfaces with your hands.