Vampire Bats and Scaredy Cats - S2-E2
Other mistake: When the Mystery Company find a torn paper in a coffin, it is written exo-6 and something else. They find later that exo is the first part of exotic. The way the paper was torn, you should be able to see the lower part of the missing letters.
Other mistake: Carmine throws the gun on the couch and it goes off. The bullet hits in the opposite direction the gun is pointing.