Though meant as a lighthearted riposte, the comment clearly had a great deal of truth to it. It was easy to attach "terrorist" to any Arab attack - even against a military target such as the bombing of the U.S. Marine barracks in Lebanon in 1983 after the Reagan administration had joined hostilities against Muslim forces by having U.S. warships lob shells into Lebanese villages.
But it was understood that different rules on the use of the word "terrorism" applied when the terrorism was coming from "our side." Then, no American reporter with any sense of career survival would think of injecting the word "terrorist" whatever the justification.