Josh used Chris' Melee moves during the oil refinery when he is a temporary partner. The most notable being the Hook and the Stomp. Also, while acting as a temporary partner at the oil refinery Josh can participate in Melee Combos, using the Haymaker and Backhand.
If the player's character enters dying status, Josh can save them if he is closer to them than the CPU partner, he will however not attempt to save you if your partner is nearby. However, Josh will not save you if you are grabbed by an enemy, regardless the distance between the player and the partner.