When Jenny Shepard is in the hospital talking with the old man, she gives him a cigarette. The color of the cigarette box in her hand changes from red, to green, then back to red.
When Director Shepherd picks up Trent Kort in Paris, the interior shot of the car shows an agent in the front passenger seat looking into the back seat. When it switches to an exterior shot of the car, the passenger seat is empty.
Abby states that the phrase "grasping at straws" is ambiguous. It is not. The phrase does not refer to drinking straws, it refers to the shafts of wheat, barley, or other grain that are left after the grain is harvested, which is called "straw."
Ducky states that the ultimate cause of death in most drug overdoses is myocardial infarction (heart attack), it is actually respiratory depression. There are some drugs that can cause a fatal heart attack in high doses, the most common being stimulants like cocaine, amphetamines and MDMA (ecstasy), but these drugs make up the minority of fatal drug overdoses. The majority of fatal drug overdoses are caused by central nervous system (CNS) depressants like barbiturates, benzodiazepines and most commonly opioids. In a fatal CNS depressant overdose death is caused by hypoxia (lack of oxygen in the brain) due to respiratory depression as a result of the nervous system being unable to conduct nerve impulses that cause the chest and diaphragm muscles to expand and contract; without them functioning carbon dioxide can't be expelled from the lungs and fresh oxygen can't be inhaled.
NCIS has state-of-the-art security systems like biometric retinal scanners to access places like MTAC and the evidence garage. Yet their most sensitive evidence is locked inside a vault with a simple analog combination lock on the door.