Ahsoka came into the room seeing Rex staring at his pistol absent mindedly tracing the grooves with his finger. She had been there that day when Fives tried to explain what the chips were for and what they meant for the republic. When Fox ran into the warehouse yelling at Fives to put his hands up. Fives snapped, picking up one of Rex's pistols and aimed it at Fox as he yelled back "GET AWAY FROM ME". Everything after that was in a haze.
The next thing she knew the smell of burnt flesh permeated the air. Fives falling to the ground with a blaster bolt in his chest and Rex by his side holding him as he yelled for someone to get a medic. Then quieting to hear Fives last words, after that the room was deathly silent, Rex lowered Fives limp body to the floor, a tear slipping down his face and landing on Fives chestplate. He got up and before Ahsoka could react Rex had tackled Fox making them both fall. Fox tried blocking the punches with his hands and arms only for Rex to shove them away. The clones and Ahsoka pried him off but not before Rex landed one more punch that knocked Fox unconscious.