Hush! Not so Loud!
Just re-watching RotS, and the line suddenly grabbed me...
After Obi-Wan escapes in Grievous' fighter, Anakin returns to Padme's apartment, and there are these interesting lines of dialogue...
R2-D2 *Frantic whistles and chirps!!!1*
C-3PO "Hush! Not so loud!"
What did Artoo say that 3PO tried to silence? Did he say "Annie's flipped his lid and slaughtered everyone in the Jedi Temple?" I read that in one of the NJO novels, Artoo shows Luke a holorecording of Anakin killing Padme on Mustafar, could it be that he knew what Anakin had done all along and just couldn't tell anyone?