One of the Press-Gazette reporters - not sure which one anymore - tweeted on the day of the announcement that the terminology used is that which indicates that his contract wasn't being renewed by the Packers. Not sure that is the case and the guy at the Journal-Sentinel who usually jumps on ANYTHING that could be remotely negative didn't comment in the same manner. If I were a betting man, I'd say that Greene's departure was by mutual consent.
Anyone remember the play in the NFC Championship game following the '96 season where Greene broke through and by all measures SHOULD have had Favre sacked, but Favre dumped the ball to a running back I believe, with Greene wrapped around his legs? That was just one of those memorable plays ... anyway ... good luck to Greene and a big thanks for your service. Really.