At the 1:12 mark in the video above, we get to see and hear the conversation between Kaepernick and two offensive linemen after San Francisco scored a touchdown one play after the linebacker's illegal hit, then came off the field.
Kaepernick: "I got you, I got you."
Joe Staley to Kaepernick: "I hear you about that, but we're setting a precedent. No one is (expletive) hitting you late."
Staley, you'll remember, was flagged for an unsportsmanlike-conduct penalty on the play. The NFL later ruled he should not have been penalized.
This clip and more aired on NFL Network's "Sound FX," which can be seen every Wednesday night. This is one of the best shows on television during the football season. You should watch it.