When Tommy returns to the apartment and finds Lum in bed, Lum calls Tommy his "nephew". But throughout the rest of the episode, Lum says Tommy's father was his son, he calls Tommy "grandson", and the two siblings refer to Lum as their grandfather.
While dealing with a snake, Jack tells Ryan that it is a highly poisonous Coral Snake. However due to the markings, it is blatantly obvious that the snake is a Scarlet Kingsnake which is non-venomous.
Jack uses a straw as a blow gun to fire the needle to kill the tattoo snake, when he could just stab it with the needle.