Continuity mistake: Robin is chasing Red X. Red X throws a net of some kind onto Robin, then Robin says, "I'm fine. Get X. Go." and points toward Red X. Later, we find out that this was actually a hologram of Robin, when Starfire accidentally activates it again. However, this time, the hologram of Robin does not point after his dialogue.
Continuity mistake: When the Wicked Scary Monster first reveals itself in the Titan's Tower, we see the Titans huddled together in chibi-form after the commercial break. At first we see the Titans cowering behind Robin, who is standing in the middle, but when we see the Monster again up front, suddenly Starfire has taken the center and Robin stands between her and Beast Boy.
Plot hole: After the battle, when Robin tosses Beast Boy the Brain for freezing, the Puppet King is seen among the assembled Titans (on the right, next to Herald and Jericho). Somewhat odd, considering that the Puppet King is a villain and not getting frozen up like his compatriots.
Continuity mistake: Within the timestream, Starfire rips off Warp's vortex regulator with her left hand. She still has it in her hand when she first shields her face with her left arm, but as we see Warp dropping out of the timestream and Starfire following right afterwards, both of her hands are empty.
Continuity mistake: The clasp on Raven's cloak also serves as an alert and tracking device, as we could see in "How Long Is Forever?" Robin, Starfire and Cyborg, whilst tracking Raven, find the clasp lying on a ledge in the sewer. But as they encounter Beast Boy as the super-werewolf and Raven hanging from his teeth, her cloak is still secured with the clasp.
Continuity mistake: The animated video shelf which goes after Beast Boy uses red and grey DVD cases as eyes and teeth. When Beast Boy roars at it as a T-Rex, the shelf loses its "eyes" and "teeth" out of fright, but when Beast Boy charges into it, it suddenly has them all back on.
Continuity mistake: After the video rental clerk shoves the Wicked Scary DVD into Beast Boy's face, the scene fades to the evidence room where Robin is depositing Control Freak's remote. In the showcase to the left which holds the masks of Slade's robots, we also see some of the Puppet King's Titan puppets and his soul-switching control, which got crisped in blue fire in first season's "Switch"; therefore it should not be on display. (Switch to slow run to detect it; it's rather difficult to catch on normal speed.).
Other mistake: Beast Boy and Wildebeest fight in a cage suspended in an endless room, with no solid ground underneath. But during the fight both combatants keep stepping onto the gaps formed by the cage bars without their feet falling through, as if the cage bars on the bottom side are merely painted onto a solid surface. For instance, watch Beast Boy's feet when he turns into a skunk.
Continuity mistake: The Titan Communicators' lids depict the Titan's logo: a white T in a black circle, encased by a yellow rim. When Robin calls up the other Titans after recovering from his paralysis, the lid of his com device has a black T in a rimless yellow circle; later it has the standard design described above.