Is prostration of forgetfulness (sujud al-sahw) required if the Imam makes a mistake in the places for saying "Allahu Akbar" (takbir) and "Sami' Allahu liman hamidah" (tasmi' )?

The "Takbirat al-Intiqal" (transitionary Takbirs) and saying "Sami'a Allahu liman hamidah" (Allah hears those who praise Him) are Sunnah according to the majority of scholars. Prayer is not invalidated by intentionally or unintentionally omitting them. Performing them in the wrong place is akin to omitting them. If the Imam unintentionally omits them in their proper place, some scholars hold that he should perform the prostration of forgetfulness (Sujud al-Sahw). The worshiper behind the Imam (Ma'mum) is not required to prostrate as long as the Imam does not prostrate. The Ma'mum should advise the Imam and draw his attention to this matter with wisdom and privately.