I think it is the same in France as it in in the UK.

In French law, truth is not required for a statement to be defamatory, but intent is. Intent is usually obvious, for example, if I am saying a restaurant owner poisons his clients, there is no way I am not intentionally hurting his business, it is defamation.

However, if I say that Benn Jordan supports Israel's occupation of Gaza in a neutral tone, like Gemini does here, then it shows no intention to hurt. It may even be seen positively, I mean, for a Palestine supporter to go to Israel to understand the conflict from the opponent side shows an open mind and it is something I respect. Benn Jordan sees it as defamatory because it grossly misrepresent his opinion, but from an outside perspective, is is way less clear, especially if the author of the article has no motive to do harm.

If instead the article had been something along the lines of "Benn Jordan showed support for the genocide in Gaza by visiting Israel", then intent becomes clear again.

As for truth, it is a defense and it is probably the case in the UK too. The word "defense" is really important here, because the burden of proof is reversed. The accused has to prove that everything written is true, and you really have to be prepared to pull that off. In addition, you can't use anything private.

So yeah, you can be convicted for hurting a quack doctor using factual evidence, if you are not careful. You should probably talk to a lawyer before writing such an article.