Welcome, Auggie, glad to have you aboard!
No, I don't think that was a mistake. In fact, it was probably another example of FFC's fanatical attention to detail. It was probably an "official" visit of the President with important businessmen, and probably was transcribed either on tape or by secretaries "for the record." So, standard operating practice was to make sure that, even though the President spoke English, a simultaneous translation was made in Spanish "for the record." If you use the "search" function at the top of the page, you'll find at least one thread on this subject in the last few months.
Other mistakes in GFII: Probably the one that's most mentioned is when the Senator asks Michael if he was responsible for "the murder of heads of the Five Families in 1950." First, there were four other families. Second, it happened in 1955.