When Randall shoots TC, no empty shell is ejected. Then as Randall chases TC into the woods, he pulls the slide to cock the pistol, and no empty shell or new round flies out. the nature of a semi-automatic pistol is to eject the empty casing after firing and automatically load a new round into the chamber. So cocking the slide would have ejected the new round.
TC, being a Marine and having worked special operations, would not have fled once he had taken down Randall.