south sydney secured a bitter 18-17 victory after a last-gasp penalty .
bulldogs were leading until the referee awarded rabbitohs a late penalty .
rabbitohs converted the penalty and went on to win the game .
as officials made their way off the field , they were pelted with missiles .
one of the officials was taken to hospital with broken shoulder .
canterbury coach has apologised for the actions of his club 's supporters .
bulldogs ceo said the club has called for a life ban on fans involved .
police have identified two people for allegedly throwing bottles .
inquiries to identify others involved in the attack are continuing .