Don't want to speak for ChiTown here, but I believe Nick's testimony was more or less accurate. Nick was either extremely truthful or a good liar. Considering the emotions he displayed on the stand I'm going to go with the former.

There were several "Annerenos/Annerinos"; Steve, Sam and John. Steve was the guy Chi talked about who worked under LaPietra and Sam was a low-level guy involved with the chop shop rackets in Jimmy Catuara's crew. He was later killed by the Wild Bunch. Sam's cousin John, who worked for the city of Chicago, was also killed after a botched murder plot involving the death of a cop. John's death was more than likely a personal matter as opposed to anything Outfit related.