That's not how defamation works. You're saying that if the statement is out there, surely people will do a deep investigation into the correctness of it?
OP was saying that even the sentence "bob says that jim is x" is defamation because readers will take it as "a ringing endorsement of bob's statement", which is patently untrue unless you are a little kid.
It is not patently untrue. It wholly depends on the reader’s opinion of Bob. Also most people’s intelligence is not that much greater than that of a little kid. They are only more knowledgeable, but not necessarily more intelligent.