In the hadith of Ibn Buhaynah, the Prophet (peace and blessings be upon him) did not ask for details; does this indicate a general ruling on interrupting the prayer absolutely, even in the second rak'ah?

The questioner : The Prophet (peace and blessings be upon him) did not ask the person praying for details in the hadith of Buhaynah; does this indicate a general ruling?

The Shaykh : And what is meant by the general ruling?

The questioner : That it is not permissible to

The Shaykh : That he interrupts it, even if he was [in the second rak'ah]. The Messenger [of Allah] said: This indicates that it was in the first rak'ah, because if it had been in the second rak'ah, he would have said, "Is the Fajr prayer three [rak'ahs]?" It is not possible for the Fajr prayer to be four [rak'ahs] unless it was before the iqamah and he was in the first rak'ah.