I get that some of you are going to be quick to say "Fernand's a scumbag" and you might be right, but I don't know him well enough to lean one way or another.
However, what I do know is his side of the story, which he elaborates on for close to an hour here:
There are subtitles, and while they're not perfect, they're more than fine. (I speak French, so I understand the interview without the subtitles)
I found him to be convincing and, most importantly, he has receipts. He has a signed contract to be Slim Trabelsi's manager, he has texts messages (which are provided in the video), etc.
What stood out to me is the principled stance he has: Ali, on multiple instances, has swept up fighters that were being managed by virtually unknown managers so that he could bring them under the Dominance MMA umbrella and the original managers were left holding their dicks. Fernand is standing up to Ali's bully tactics to tell him, if you want to steal my fighter that badly, here's the cost. If you don't want to pay that, he'll just have to respect his contract at ARES.