10-year-old Dick has a portrait of Zucco from a "wanted" poster that he shows to several people. In some shots, the poster's borders are perfectly regular, as if cut; in others, they are irregular, as if ripped; and sometimes, there is a combination of both.
In the credits of Robin's Reckoning Part I, Robin's younger self is cited as "Robin (Age 10)." But in Part II's credits, it cites "Dick Grayson (Age 9)."
Zucco shoots a burst against the ceiling. When his face is shown, the submachine gun is releasing some three bullet casings per second. When his feet are shown, only one casing per second drops to the floor.
When Robin confronts Zuko, Batman says, "Enough. You can't let your emotions get the best of you." But his mouth doesn't move.