What is the case of عَمْرٌو in تَشَاتَمَ زَيْدٌ وَعَمْرٌو?

Advanced Sarf Application: Ambiguous Forms, Weak-Letter Reasoning and Error Correction

• Nominative, coordinated with Zayd
• Accusative direct object
• Genitive due to a preposition
• Indeclinable on sukūn