The video shows that Davis had words with Distin before punching the man, who was seated while dining with his wife, Ivy Bell, and the couple's 5-year-old son.
Distin's family is seen trying to stop the attack, but they were no match for Johnson and Davis, seen pummeling the victim, who suffered broken ribs and facial bruises.
Yesterday, Johnson, 21, pleaded guilty to aggravated assault, robbery and conspiracy.
It's not clear why the cousins attacked Distin, Assistant District Attorney Morgan Model Vedejs said, adding that the victim's son screamed as the defendants "beat the crap" out of his father.
She asked Common Pleas Judge Rayford A. Means to sentence Johnson to seven to 15 years in state prison.
"This is egregious, it's scary. Literally, anyone can just be sitting in a restaurant having dinner and either make someone angry, look at them the wrong way, say the wrong thing and be attacked," Vedejs said.
Means called Johnson and Davis "cowardly" for having assaulted the older man in front of his family. He then sentenced Johnson to a little more than what the prosecutor had asked for: 7 1/2 to 15 years in state prison to be followed by five years of probation.
Upon hearing the sentence, gasps erupted from Johnson's relatives, who included his mother, grandmother, stepfather and aunt.