I wish him luck proving 'criminal' slander. Slander is a 'tort' or civil matter.
It's a pretty basic thing to know the difference, and thus ignore the silly threats.....he clearly isn't talking to anybody with even the minutest understanding of the laws of France, UK or US or anywhere else that i can think of.
Further, slander is general considered a 'spoken' defamation whereas libel is the written or published form.
HIs understanding of law is almost as in depth as his understanding of aviation!!!