TB do you think he suspected him at the house or did he want to scare Pentageli into thinking he suspected him....

OR

Could this have been an error in the film. I know that the Pentangeli role was initially to be a continuation of Clemenza, which didn't happen because of this Castellano business. I think one plot line was that Clemenza would betray the family, which would allow for a line like that along with the famous (and IMHO) ambiguous "Michael Corleone says hello" line.