Sykes also wrote on the Taiping Rebellion holding the British Government guilty of unjustifiable aggression towards China. He also held the British responsible for precipitating the 1857 rebellion by being insensitive to local customs, citing the earlier case of the Vellore mutiny. In a commentary to the British media which had suggested that the mutineers were using greased cartridges, one of the immediate causes of the uprising, against the British he pointed out that they were all using 'Brown Bess' and conventional musket ammunition. He was one of the founding members of the Asiatic Society of Bombay.