Revealing mistake: "Alan a Dale": Lady Mildred rides side-saddle. But when Gisburne gallops away with her, some shots reveal that the stunt woman riding the fast-moving horse is astride it full straddle. Her skirt is blown back just enough to see a brief glimpse of the stunt rider's real leg on the horse's right, and the fake pair of legs in side-saddle position on its left. For just a moment, the lady appears to have three legs. (00:20:00)
Other mistake: When Spike is thrown out of the base by Megatron at the end of the episode, Optimus calls him 'Splik'.
Revealing mistake: When Jonathan has the red balloon float to the sad young girl, we can see the balloon's guide wire just as she takes hold of it, while she and her brother are on the bench. (00:06:30)