How about Jimmy Altieri? He was killed because they thought he had flipped. Later they find out they confused him with Big Pussy, who was flipped at same time.
Jimmy did flip. True,they did confuse him with Pussy,but he was also a rat in his own right. Remember the conversation in Tony's basement where he was trying to get Tony to talk about some illegal activity?. It was obvious that he had flipped and was wearing a wire,so he would have been hit at some point anyway.
