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.
Other mistake: Among the Titans groaning over Beast Boy's "brainfreeze" joke, we see XL Terrestrial, the pale-turquoise alien-looking guy with two antennae who can grow to large size. Again a mix-up of hero and villain identities, since XL was in the H.I.V.E. and the Brotherhood of Evil and should therefore not be among the young heroes. You will also see the Puppet King by Jericho.
Continuity mistake: When Kid Flash and Jinx arrive to give a helping hand, the remaining H.I.V.E. Fivers stare at her, aghast about seeing her on the heroes' side; Billy Numerous even points at her. Before (when Cyborg is slammed into the stairs) and after (when Kid Flash races off into the fray) that particular shot, however, the H.I.V.E. Fivers' stances and expressions just remain the same.
Continuity mistake: Más y Menos figure out how to use Professor Chang's Cryogenic Machine to unfreeze their fellow Titans and do the reverse with the opposition. But the few times where they are seen actually activating the Freeze option - Professor Chang and his assistants, and later the HIVE Five -, they push a different button in each instance.