In a flashback, it is revealed that Tony received his Mighty Mouse stapler from his old boss, Frank Raimey, as a result of him winning the Baltimore Police Department Pool Championship for the second year in a row. Raimey admits that he got the stapler from a garage sale.
In one of the flashbacks to his days as a Baltimore PD detective, DiNozzo says to his partner, "Who'd want to be a Navy cop. I'd rather have the plague." Not only is he now a Navy cop, the 'Very Special' NCIS Agent, Anthony DiNozzo; in SWAK (2005) he was infected with pneumonic plague.
The first episode to have the red slash through Osama bin Laden's picture on the "Most Wanted" wall. It was obviously added post production, as it was only two days earlier that the al Qaeda leader had been killed by a U. S. Navy SEAL team.
Gibb's rule no. 35: Always watch the watchers.
In Gibb's flashback Special Agent Pacci says "My ulcer's killing me again. I'm telling you, this stomach is going to be the death of me." Although not the actual cause of death, but in Dead Man Talking (2004), his body is found mutilated in an elevator.