Sure, there are no sahih ahadith proving that it even took place on the night of the 27th, but great 'ulama have favoured that view - it could be wrong, it could be right, just like most matters. From these scholars were Imam an-Nawawi ash-Shafi'i and one of the greatest Huffadh of Hadith, the great Hanbali author of 'Umdat al-Ahkam, al-Imam 'Abd al-Ghani al-Maqdisi, radhiy Allahu 'anhuma. Other scholars, differed, no doubt, but it need not be an issue of contention, and certainly not an oppurtunity to target scholars and their understanding of ahadith.was-salam