Chad Billingsley probably should've thrown behind somebody before he got knocked out, but he didn't, and so going into Game 3, the Dodgers and the Phillies all knew retaliation was a possibility. And it became a near certainty after Martin was hit in the knee by Jamie Moyer, even though Moyer clearly didn't hit him on purpose. Within the baseball code, there is a sense that enough is enough.
Martin got knocked down again by Clay Condrey in the second inning, and slammed his helmet and screamed angrily in the dugout. And as Victorino watched this play out, he had to realize that he was due to hit third for the Phillies in the top of the third inning and was probably going to be a prime target. As Jimmy Rollins batted with one out, Martin twice gave demonstrative signs for Kuroda to throw the ball the inside, and shifted his body so that he was almost behind Rollins' knee. Kuroda threw a fastball to strike out Rollins; two outs, nobody on base, the Dodgers with a big lead.
The conditions were perfect for retaliation. Victorino probably walked to the plate assuming that he was going to get drilled. Once again, Martin gave a particularly demonstrative sign to Kuroda for a fastball inside, and again, Martin set his target nearly behind Victorino -- and Kuroda threw the ball over Victorino's head.