Could just be gas guns, cable guns etc. Movie Batman hasn't THROWN anything worth mentioning in decades. Quite a world away from that John Byrne sequence just after the 80s reboot where Bats wrist-flicks a plain batarang from behind his back, out a penthouse window, over the top, through the opposite window and into the Joker's head. SO plausible.
What's my point, here? God, I'm gettin' old.....