McGee, Abby and Palmer are seen standing next to Ziva as she is taking the oath. Citizenship ceremonies are conducted with all new citizens sitting together, and families on the back/sides/in the balcony (depending on the size of the venue). You would NEVER be seated with your guests. Also, most don't allow more than two guests, certainly not the five the show implies are supposed to be there.
The drink that Gibbs drinks down after saying "I don't usually drink scotch" is far too dark in color to be scotch. Scotch of any age is a golden brown. The contents of Gibbs' glass was almost black, closer to the color of amaretto or a dark rum.