Correct. If the enemy just sits there and makes a ranged attack at someone other than the fighter, the fighter gets to swat him twice--once from CC for making an attack not including the fighter, and once for making a ranged attack adjacent to the fighter.
A better strategy would be to shift away from the fighter, eat the CC attack, which does not stop their movement, and make his ranged attack in a spot which does not provoke an OA.
If he 'Moves' away from the fighter, he takes the risk of getting hit with an OA, which would stop his movement while he's still adjacent to the fighter. But this time, if he were to make a ranged attack against a target other than the fighter, the fighter doesn't get to make a second OA against him, only the CC attack.
In any case, sucks to be him.