Visible crew/equipment: When Otho is doing the Seance, Adam and Barbara appear in their wedding clothes and then float above the table. When Lydia releases Beetlejuice, everyone gets up and leaves the table, and in this wideshot the black wires that Adam and Barbara are suspended from are visible. (01:15:25)
Revealing mistake: At the end, as Beetlejuice's head shrinks, the collar has a line around it, showing where the two images were superimposed.
Revealing mistake: When Maxie and Juno are jetted through the ceiling, check the stiffness of their bodies: they've been replaced by mannequins. (01:19:20)
Answer: No; it was left strictly to the imagination of the audience.
zendaddy621