Continuity mistake: When Starfire is force-fed pie by Mother May-Eye, she swallows a rough clump of pie before pretending to be mind-controlled. But after may-Eye leaves, her tongue evicts a whole pie from her mouth, plate and all.
Continuity mistake: After Mae-Eye is banished back into the pie, the Titans assemble around it to ponder its fate. In the shots where we can only see their feet, they are positioned (clockwise, starting at 1 o'clock): Beast Boy, Starfire, Robin, Cyborg, Raven (who takes Silkie's place). But when we see their faces from the ground up, their positions are (taking the new perspective into account): Beast Boy, Robin, Starfire, Cyborg, Raven - on the whole meaning that Robin and Starfire switch places from one cut to the other, and back again.