After Micheal becomes head of the Family in The Godfather, right after Tom was removed from consigliere, Micheal says that Carlo would be the right hand man in his business in Nevada. Vito also says he is happy for Carlo.
Now my question. if Don Vito is smart enough to figure out it was Barzini all along then he would have also known that Carlo is the one who lured out Santino out of the house so that Barzini's henchmen can murder Santino.
My question is did Vito know this and ignore it?