Please read WP:BLP. It states: “This policy applies to any living person mentioned in a BLP, whether or not that person is the subject of the article, and to material about living persons in other articles and on other pages, including talk pages.” (emphasis mine) 

 ::::::There is no question that Williams made statements in the helicopter incident that were not true. There is no evidence that they were made intentionally to deceive or even not, as he claims, poor recollection. But, the editor in question has gone much farther, using the perjorative word “lie”, over and over, in reference to situations that are he said/she said, or, not even clear accusations of lying. That is, the editor is the one making accusations of lying without evidence. This is a gross violation of WP:BLP.