During Baltar and Caprica Six's flashback, Baltar informs Caprica Six that he would be willing to let her take a look at the defense mainframe. When Caprica Six says that her employers would be very grateful, Baltar says that he isn't doing it for them, but for her. He continues by saying the following:
Baltar: Because if anyone finds out, I could get my head cut off.
That was precisely how the Baltar character was executed by the Cylons in the 1978 Battlestar Galactica feature film.