When Veronica (Kristen Bell) calls Cliff (Daran Norris) to ask him about the newspaper ad, he's with his client Loretta Cancun (Ameenah Kaplan). This is the same client mentioned in the pilot episode, Pilot (2004), that Veronica helped by exposing the shady way the strip joint keeps their liquor license.
Veronica's (Kristen Bell) threat to tell Tad's Naval Academy classmates that Tad (Jeff D'Agostino) is gay (even though he is not) is a potent one because at the time the episode was filmed and aired, the US Military's policy commonly known as "Don't Ask, Don't Tell" that prohibited any non-heterosexual military member from revealing his or her sexual orientation was still in place. That policy was in effect between 1993 and 2011, and was a replacement for the previous policy on the matter, which was a total ban on all homosexual service people.
This episode was originally called "Tit for Tad".
This episode's title, "M.A.D.," refers to the military doctrine of "mutually assured destruction," in which it is assumed that neither one of two heavily armed military enemies (usually nuclear superpowers) will dare to attack the other first because both possess such large stockpiles of deadly weapons that there is no scenario in which a war between them would not spell destruction for them both. The doctrine was best known during the Cold War era, when military strategists hoped that it would prevent nuclear war between the US and Russia (or Russia's allies).