The character Sam that exchanges a bit of dialogue with Conway during "Operation Frodo" was voiced and drawn to look like the artist and actor Sam Ellis.
Quadroon is a racial slur meaning 1/4 black 3/4 White.
First occurrence of the repeated "Danger Zone" gag.
"Charles Whitman sampler" is a dual reference. Firstly, to Charles Whitman, a former U.S Marine and engineering student who engaged in a shooting spree using a sniper rifle at the University of Texas at Austin campus in 1966. Secondly, to the Whitman's sampler, a popular assortment of boxed chocolates.
This is the second time Brett gets shot in the office. Archer is the one who shoots him both times.