All true, and they both were 'enabled' by factions of the government.
Based on the accounts I have read, it is very likely there was a second gun being fired in the RFK assassination. But it was 'friendly fire'. One of the armed security attachment 'may' have pulled his weapon and fired off a shot. Maybe he even hit Kennedy.
Maybe....
Google Thane Eugene Cesar for the name and accounts of the actions of RFK’s security guard.
Also look into the coroner’s report, where Thomas Noguchi places Sirhan continually in front of RFK and unable to deliver the fatal bullet which was shot from behind.
The more important questions concern how Sirhan happened to get to a position where he could shoot RFK. Sirhan was not a criminal genius, so if you focus on who helped him to be in the right place at the right time then you are in a better position to conclude that he couldn’t have been acting alone.