Casey Gant (Jonathan Bennett) is a member of a cult called the "Moon-calf Collective". By definition a moon-calf is a foolish person.
At 8:23 her dad asks Veronica in perfect French "Nous comprenons nous?". English "Do we understand each other?".
The episode title is a nod to the widely-used phrase "drinking the Kool-Aid," which refers generally to the act of buying wholeheartedly into a belief, preference, or idea, and specifically to the 1978 Jonestown cult suicides in Guyana, in which cult leader Jim Jones poisoned (or convinced to self-poison) over 900 of his followers with a mixture of grape Flavor Aid, Valium, chloral hydrate, and probably cyanide.
When Veronica first sees Clarence Wiedman, he is driving a new Chevy Malibu with steel wheels and wheel covers. When he pulls into the Kane Software parking lot, it is an older Malibu with aluminum wheels.