Visible crew/equipment: After the scene where Selina shocks the clown henchman with the taser, it cuts to the Mayor thanking Batman. As they walk down off of the walkway and continue down the road, if you look on the floor behind Batman you can see black camera tracks on the floor of the raised, bridge walkway. (00:16:15)
Trivia: The Christmas ball scene is symbolic: since it is a masquerade party all the guests are in disguise. The only guests who aren't wearing masks are Bruce Wayne and Selina Kyle. This implies that their real personalities are Batman and Catwoman respectively, and that their public persona is the real disguise.