Barrett was “going to be in huge trouble,” observed commentator Justin Marshall at the time, since the blow was late and “flush on the jaw.”
Barrett will miss the Crusaders’ games against the Rebels, Waratahs, and Force, and his availability for the Crusaders’ Round 13 encounter against the Brumbies will be decided by his completion of World Rugby’s Intervention programme.
Meanwhile, two other New Zealand were also slapped with three-week bans: Hurricanes hooker Asafo Aumua and Highlanders lock Josh Dickson.
Dickson copped a ban after he was red carded for an early hit on Tevita Mafileo in their loss to the Hurricanes at Dunedin on Saturday.
Aumua was also banned for three weeks for making head contact in the same game, although he was not sanctioned during the match.