Interestingly the statement that “ defamation requires a provably false statement of fact “ is not true in all jurisdictions. German law makes a distinction between „Verleumdung“ which is indeed like defamation and “üble Nachrede“, which only requires a statement to not be probably true.
In Japan, defamation doesn't require falsehood. Yes, you can be punished for defamation for having told the truth!
For example, saying that someone is involved in a crime it a way that make people think he is guilty when he is, in fact, the victim. For example, "Mr.X is involved in a series of robberies" when he has been robbed.
Other cases where defamation can be invoked is with illegally obtained, private information. For example "Mr.X has been diagnosed with $medical_condition, so...", a clear violation of medical privacy, especially if the one making the accusation is a doctor.