Both players were cited after Rhodes used a dangerous headlock to clear Piutau at a ruck. The wing retaliated by twice punching Rhodes in the head.
Hearings took place in Wellington on Monday and judicial officer Nick Davidson QC released his decision yesterday.
Rhodes was found guilty of the dangerous tackling of a player without the ball and was suspended for six weeks.
Rhodes had flipped Piutau over in a dangerous manner "placing his head and neck at serious risk of injury".
Davidson added video evidence showed Piutau in a highly compromised and dangerous position. Rhodes is ruled out of all rugby until the end of July, a period that will encompass six matches.
Piutau was found guilty of punching but has not been sanctioned due to the "exceptional circumstances" of the incident.
While Piutau admitted the foul play, he had been "seriously compromised" in the incident involving Rhodes. Piutau's reaction was that of someone who had been "seriously endangered".
Davidson added to impose a sanction "would not reflect the effect on Piutau of the incident and a reaction that was the product of shock, rather than retaliatory intent".
