Dark Skies - S5-E8
Character mistake: Higgins and TC are investigating a drug smuggler camp in Maui. TC sees a box of cigarettes and says the people in the camp must be Latino because the cigarette box is in Spanish. Wrong. The box says Cigarillos, which are small, short cigars. If the box was in Spanish it would say Cigarrillos, which is cigarettes in Spanish.
Character mistake: One character says a concentration of 0.09 parts per million in the water is bad: "if it were salt it'd taste like you were drowning in the ocean." Rubbish. The concentration of salt in seawater is about 35,000 parts per million.