This story alone destroys the claim that the Quran is preserved but I have another one for you.
According to the hadith, some Qur’anic verses were written on a piece of paper and were lost when a goat ate it:
[Narrated ‘Aisha] “The verse of the stoning and of suckling an adult ten times were revealed, and they were (written) on a paper and kept under my bed. When the messenger of Allah expired and we were preoccupied with his death, a goat entered and ate away the paper.”
Musnad Ahmad bin Hanbal. vol. 6. p. 269; Sunan Ibn Majah, p. 626; Ibn Qutaybah, Tawil Mukhtalafi ‘l-Hadith (Cairo: Maktaba al-Kulliyat al-Azhariyya. 1966) p. 310; As-Suyuti, ad-Durru ‘l-Manthur, vol. 2. p. 13
It was narrated that ‘Aishah said: “The Verse of stoning and of breastfeeding an adult ten times was revealed, and the paper was with me under my pillow. When the Messenger of Allah died, we were preoccupied with his death, and a tame sheep came in and ate it.” (Hasan)
Sunan Ibn Majah 3:9:1944
My thoughts on this subject: it sounds very odd and even unbelievable that the only two verses to be eaten by a sheep/goat are the only two verses that are extremely controversial! Muhammad would have got so much heat from the incident of Aisha being accused of “sleeping with Safwan” as well as the crazy suggestion that breast feeding an adult to make them your maharam (legally your relatives) is an absolute joke! I can understand why he (and the Sahabah) would have wanted those verses destroyed. To suggest they are eaten by a goat is also ridiculous. The Quran was supposed to be preserved by memorisation and not writing! Can you see why this story destroys the argument that Allah promised to preserve the Quran (Quran 15:9).