Answered by Sidi Salim Ghisa
As I was leading the prayer, at one point, I forgot where I was in the prayer, and from going from the sujud, I was supposed to go to the sitting position and finish off the prayer, but I thought, I was supposed to stand again, so for a second, I got a quarter way-up, realised what I was doing was wrong, and quickly went into the sitting position, Did this necessitate a sajda sahu, because I didn’t perform one
Bismillah Hirahma NirRaheem.
The act as explained below would necessitate additional forgetful prostrations. It is stated in both Durr-e-Mukhtar and Ghuniya as follows:
a) If a person stands in error in the first sitting position where he was supposed to sit and pray the Tashahhud then if he has stood fully (i.e. in the standing position for the third cycle of prayer) then he should NOT return back to the sitting position, but complete the Salaah as necessary and perform two forgetful prostrations in the last sitting position.
b) If a person had not fully stood up but had actually started to stand and then realised that he was supposed to sit, he should sit, prayer Tashahhud and then continue his salaah but STILL MUST PERFORM the two forgetful prostrations in the final sitting position.
c) If a person had fully stood up but then sat back down again (to pray the first Tashahhud) then he should also perform two forgetful prostrations in the last sitting position. However, if he does this his Salaah will count but he will have committed an act against the Sunnah, hence sinful and therefore he should stand immediately back up and continue his Salaah and perform the two prostrations at the end. (Durr-e-Mukhtar, Ghuniya) [Taken from Urdu version of Bahar-e-Shariah)
Therefore if the above was not done, it would be necessary to repeat the Salaah.
Of Course Allah knows best.
Muhammad Salim Ghisa