A Hong Kong man whose attempt to defend his ex-lover from her boyfriend turned fatal was found guilty of manslaughter and jailed for three years by a court on Wednesday.The High Court heard Shum Man-fai, 44, punched Wong Yat-ming, 37, after the younger man assaulted his ex-girlfriend and plunged towards Shum upon seeing them walk together in Kowloon City on July 16 last year.Wong’s head hit a rack and he fell to the ground, resulting in three fractures to his skull.He was rushed to a hospital,…