Reciting the Du'aa Qunoot only after the Ruku

Q: Salaah-21: The Imaam forgot to recite the Du'aa Qunoot in the Witr salaah and realised his mistake only when in Ruku. He then recited the Du'aa Qunoot after standing up from Ruku, after which he proceeded directly in Sajdah without repeating the Ruku. Is the salaah valid? If he needs to repeat the Ruku and a latecomer then joined the Imaam in the second Ruku, will the latecomer be part of the Rakaah just performed?

Answer: The salaah will be valid and there is no need to repeat it because the Ruku will not be invalidated by the recitation of the Du'aa Qunoot. It was however wrong to stand up from the Ruku to recite the Du'aa Qunoot. If the Du'aa Qunoot is omitted, it is sufficient just to perform Sajdah Sahw. The person joining in the second Ruku will not be deemed to have made it for the Rakaah. And Allaah knows best what is most correct.

Fatawa Rahimiyyah vol.2