Rule reminder
Dislocation (left or right) marks a TOPIC — something already in discourse. Cleft sentences ('È il libro che hai letto') mark FOCUS — they identify which one, making an exclusive or contrastive claim. Dislocation: 'Il libro, lo hai letto?' Cleft: 'È il libro che hai letto, non il giornale.'
You want to identify precisely WHO called — it was Luca, not anyone else. Which structure is best?