When someone joins the Salah while the Imam is in the state of Ruku', does he have to repeat the Rak'ah?

Praise be to Allah, the Lord of the Worlds; and may His blessings and peace be upon our Prophet Muhammad and upon all his Family and Companions. The majority of Muslim scholars, including four Imams are, are of the opinion that whoever catches up with the Ruku' he catches up with the whole Rak'ah and the Rak'ah is complete and counted. Among the evidences for this opinion is the Hadith reported in Sahih Muslim that the Prophet (Sallallahu Alaihi wa Sallam) said: Whoever catches up with a Rak'ah with Imam he catches up with the whole prayer . Ibn Khuzaimah reported in a Hadith that reads: Whoever joins a Rak'ah with the Imam before the latter raises his back, he catches with the Rak'ah . Abu Dawood reported in a Hadith: If you come to prayer and find us in prostration, join us in the prostration, and do not count that but whoever joins the prayer while the Imam is in the state of Ruku' he catches up with the prayer . al-Baihaqi , Ibn Abi Shaibah , al-Tabrani in al-Kabeer reported through a sound chain according to Sheikh al-Albani , from Zaid bin Wahab who said: I went out in company of Abdullah bin Masood from his house to the mosque. When we reached the middle of the mosque and before we reached any row, the Imam entered the state of Ruku'. Thereupon, Abdullah pronounced Takbir and bowed down in Ruku', I followed him. While in that state of Ruku' we walked to join the rows and reached them while the people were raising their heads from Ruku'. When the Imam finished the prayer, I stood assuming that I did not catch the Rak'ah, but Abdullah held my hand and made me sit saying you have caught up with the Rak'ah . It is narrated in al-Bukhari that Abu Bakra (Radiya Allahu Anhu) came to the Salah while the Prophet was performing Ruku' and Abu Bakra performed the Ruku before he entered the row. He mentioned this to the Prophet and he said: May Allah increase your love for goodness, but do not repeat that act . The Prophet (Sallallahu Alaihi wa Sallam) did not order him to repeat the Raka'h. However, Imam al-Bukhari and some other scholars disagreed with the above opinion. al-Shawkani supported the later opinion in his famous book 'Nail al-Awtar' but thereafter, he changed this opinion and preferred the first one as mentioned in his Fatawa: "al-Fath al-Rabbani Fi Fatawa al-Shawkani". Allah knows best.