Party A preemptively accuses party B of something it expects to be or can be accused of itself. For example:
It is ironic that [alternative medicine] proponents often simultaneously tout how individualized their treatment approach is, but then claim that one product or treatment can cure all cancer. Meanwhile they criticize the alleged cookie-cutter approach of mainstream medicine, which is actually producing a more and more individualized (and evidence-based) approach to such things as cancer.
It isn't simply irony, though it does apply. Is there some name for this?