During the scene where they are sitting in Ops, discussing the different irrational fears some people have, Eric asks Nell if she has ever been afraid of people holding and speaking with puppets. Barrett Foa, who plays Eric, had his first starring role on Broadway in "Avenue Q," a play where all actors perform their character's roles while holding and speaking with puppets.
Cameron Goodman [Gloria Bryant] has appeared on Requiem (2007) as a different character. Her character there was, Maddie Tyler, an elementary friend of Kelly Gibbs, Leroy Jethro Gibbs daughter who was murdered as a child.
Nell asks Eric if he has any "irrational phobias". The question is tautological. Phobias are by definition irrational. For instance being in close proximity to a tiger isn't a phobia as it is rational to fear.