Also, the novel states that Mike instructed Clemenza personally who would have then instructed Cicci at least regarding Tessio's demise.
By the way, I think that it was a legal error for Mike to read his statement or even enter it into the record. The last thing a potential defedant wants to do is to give the other side any fodder.
As for your first point Clemenza was A) DEAD & B) A BUFFA.
As for your second point, you are correct, but Micke and Tom has a "balls to the wall" strategy in which they challenged the committee to bring someone forward to contradict Michael's statement. Obviously they didn't know Pentangeli was alive.
