the reason that it looked as though two Frenzy's were ejected is because Frenzy's battle partner... Rumble... look alike. The same goes for Rewind and Eject.. they look the same.. they just have different coloring.
Actually, Frenzy and Rumble were painted the same color, so they both looked like Frenzy. Also, with Rewind and Eject, Rewind was painted the same color as Eject. That's what the mistake is. It was an error in the coloring.