David Caruso's remarks scripted?

I remember seeing this on TV some time ago. There is one scene where David Caruso's character is screaming racial insults in the street. The other actor looks genuinely annoyed, not so much over the content of Caruso's remarks but more for the disruption of his big scene. One of the better moments in an otherwise ho-hum movie. Made me wonder whether this was scripted or whether Caruso was improvising? Anyone know?