what i ment by the "think that would fool a corleone" line was the meer fact that fredo said that he didnt know so michael would know something we dont also as you said with the call where you said fredo was visibly upset...as i had said thats how you see him...isnt there a slight..small but slight chance that FFC showed him that way so that maybe people would think he wasnt able to carry out the hit and if its true he was upset about it could that also be because he was upset at michael that he had the hit helped with the hit not thinking more of an act of revenge that was "jsut business" before realizing what he almost did