The man discussing Groundhog Day mythology with Tony in the elevator at the beginning of the episode is, in real life, CBS weather anchor Dave Price who reports on the festivities in Punxsutawney, Pennsylvania each year.
Kate's ringtone is the NCIS theme song.
When disctussing Petty officer Dillan's SEAL Training Gibbs is informed that Dillan "rang the bell" In the Navy, SEAL Training is voluntary and brutal, you can leave whenever you want but to do so you have to Ring a Bell place in an open yard, Announcing your failure to everyone there for them to watch as you slink away.
When McGee points out the killer has his watch on his right wrist. DiNozzo holds his hands foreward trying to remember left from right.
Gibbs asking Abby for a half dozen forensic results Abby states "I need an assistant" This is the first time Abby requests one, not the last. But this is contradicted in later later season when Abby is assigned an assistant who drivers her crazy.