The stamp "Melmer" on the scrap of Nazi document found in the vault is a reference to SS-Hauptsturmführer Bruno Melmer, who headed the Finance Office (Amtskasse) of the SS-Command Office (SS-Hauptamt). As such, he was responsible for the transfer of gold and other valuables stolen in concentration camps.
When Booth and Brennan are seen at the pool at the start, all of the books Brennan has around her are in Spanish.
Neither of both characters that speak in Spanish spoke with an Argentinian accent, they both talked with another accent.
Michael and Christine appear to be approximately the same age, when Michael is actually 9 months older than Christine.