Kaino was cited following the incident during the weekend's Heineken Champions Cup game between Bath and Toulouse.
Roberts was briefly knocked out following the 39th-minute incident - Kaino received a yellow card - and took no further part in the Recreation Ground clash that Toulouse won 22-20.
Kaino, who joined Toulouse earlier this year following an 81-cap All Blacks career, appeared before an independent disciplinary committee in Paris after being cited by match citing Commissioner Eugene Ryan. He pleaded not guilty.
He is now suspended until December 3, starting with Toulouse's Champions Cup game against European title holders Leinster on Saturday.
Kaino's Toulouse teammate - prop Lucas Pointud - has received a four-week ban following an incident in the Bath game.
He was initially cited for striking Bath prop Nathan Catt with his head. A disciplinary committee in Paris determined it had been Pointud's shoulder that made contact with Catt's head, and that the offence warranted a red card.
Pointud, who pleaded not guilty, is suspended until November 26.