What was the greatest controversy in anthony flew's career?

Anthony Flew was an English philosopher, best known for his philosophizing on religion. He represented the atheistic point of view, moreover, he was the only philosopher who was called „the icon of atheism“. He criticized the religious ideas and beliefs, wrote many works with atheistic attitudes, and denied existence of God on many public debates and lectures. The greatest controversy in his carrier appeared when he turned from atheism to theism, and publicly admitted that he started to believe in God. Many atheists claimed that he didn't say that, so he wrote a book: There is a God. Even after that, there were claims that this book hasn't been written by Flew, but by his friend Roy Abraham Varghese, and that Flew was in state of serious mental decline. But, Flew denied this claims too, explaining that Varghese was the one too do the physical writing because Flaw was ill, and that all the thoughts from the book are his own.