Other mistake: When Spike is thrown out of the base by Megatron at the end of the episode, Optimus calls him 'Splik'.
Other mistake: When the Decepticons shoot the monument at the end, Optimus runs to save it, you can see two Optimuses (Most likely because the animators forgot to get rid of the other prime which is just standing there).
Answer: These two were 'dinosaur' cassettes Overkill and Slugfest, then-new toys. They turn up this once and that's it, though.
Daria Sigma