What is the ruling if a husband calls his wife 'O adulteress' (Ya zaniyah) and she responds, 'Rather, you are an adulterer' (Bal anta zaani)?

Primary text

Each party is considered a defamer of the other, and both must receive the Hadd punishment for Qadhf. However, the wife cannot waive her punishment except through clear evidence (bayyinah), whereas the husband can waive his punishment through evidence or by Mula'anah (oath of imprecation).