That's exactly the way I feel P. Lawrence. I don't know if he opened the drapes, but all the statements you mentioned by Fredo, I think, were said aincerely. He could never intentionally have any family member killed.
True, maybe he was stupid/naive for not thinking it would be a hit, but that's Fredo! I still don't know for sure who killed the assassins at Tahoe, but again, I don't think Fredo had it in him to kill anyone!!
TIS