When ~Protagonist goes to the car sequence, from his POV we see ~Sator throwing the orange case back to the Protagonist and the 241/metal cube rattling around in ~Protagonist's car before flying out the window and returning to the Protagonist's hands.
From the Protagonist's POV, the Protagonist first throws the empty orange case to ~Sator and then throws the 241/metal cube to ~Protagonist.
Does the Protagonist know that he is throwing the 241 to ~Protagonist, and if so why were neither of them annihilated? If he didn't know he was throwing it to ~Protagonist, did he just think he would return to the crashed car later (i.e. after the crazy car sequence) and retrieve it?