I wondered if it was a momentary lapse by the writer, but no; Google the phrase and everyone uses it. And while going against the herd is not something I do lightly, I feel I must at least raise the question.
What the hell is everyone talking about?
“…like a knife through butter,” makes more sense, although some of we Northern Hemisphere types might like to preface “butter” with “warm” at this time of year. In its current form, though: who actually casts butter?
There’s a phrase doing the rounds among British soccer commentators of late which has sadly gained acceptance through unthinking repetition: one parrot after another referring to “stone wall” penalty decisions when they actually mean “stone cold”.
Let’s not take a similar stroll down Gibberish Boulevard, fly anglers; please…