Imam sb forgot to call the first 3 extra takbeers after sana during first rakat and he directly started surah fateha.When people gave lukmas from behind,he called the missed 3 takbeers after finishing surah fateha and then continued with the qiraat. After this,he continued the salaah as usual and everything was fine during the second rakat.At last, he finished the salaah with sahu sajdas.Few people raised disputes that the salaah was not valid.So please make it clear.
Ref. No. 1245
In the name of Allah the most Gracious the most Merciful
The answer to your question is as it follows:
In the above mentioned case the Namaz was valid.
And Allah knows best
Darul Uloom Waqf Deoband
This answer was collected from the official website of Darul Uloom Deoband Waqf. The institution is based in India and the answers are provided in accordance to the Hanafi Fiqh.