That's my understanding. Also, particularly with public figures, the entity making the defamatory statement has to have known (or a reasonable person would have

That's my understanding. Also, particularly with public figures, the entity making the defamatory statement has to have known (or a reasonable person would have known) that the statement was false. But as you say, it's very hard to see how saying someone is shorter than they are is defamatory in the first place. There would have to be some additional circumstance that makes such innocuous misinformation damaging.