Other mistake: The episode's action takes place around 11:00pm (night time), yet all the scenes show broad daylight.
The Revenge of Robin Hood - S1-E16
Other mistake: During Robin Hood's attack on the castle, the same crossbowman is seen getting shot and falling off the castle wall twice.
Surf's Up! Joker's Under! - S3-E10
Other mistake: An amazingly precognizant Dick Grayson is already wearing his surfing togs before Commissioner Gordon calls to say that Joker has invaded the surfing community. (00:04:30)
Suggested correction: Dick isn't amazingly precognizant. He's wearing swim trunks while using the rag to prep his own surfboard. Barbara Gordon was already at the beach with Skip, and Dick is heading to the beach with his surfboard as well (00:04:34).