in the same breath; hardly had the words been said
Used when someone contradicts themselves immediately after speaking, or when an action follows so quickly that the previous words are still 'wet' on the tongue. Often carries a critical or ironic tone.
See also: 舌の根も乾かぬうち (したのねもかわかぬうち)
He said he would never do it, and in the same breath started doing exactly that.
Hardly had he apologized when he repeated the same mistake.