No, it's not. There's two separate issues here. The portion you quote earlier, and the Testimonium. He's right that the Testimonium is almost universally rejected. It literally makes no sense being there.

As for the bit in Antiquities, "the brother of Jesus, who was called Christ, whose name was James," stop and consider: if Josephus is actually referencing the Jesus Christ here, then he's certainly aware of him, and presumably, his followers. Yet this is the only time he mentions it, ever. Really? That makes sense? A supposed miracle worker starts a new religion in region Josephus wrote about extensively, and yet he only mentions him one time, in passing?

Sorry, that simply strains credulity.

It makes sense if you understand Josephus's background. It is exactly the kind of mention he would use, and it shows that Christians didn't "get to" and re-arrange his writing to shoehorn in Jesus. Otherwise, if they were putting something in, wouldn't they make it agree with their own biblical account? Josephus's account is understood by a majority to refer to Jesus of Nazareth, who claimed to be the song of God.

Mini Ditka,
Do you ever use the term Santa Claus?

In context, it's pretty clear he's not. And I don't see how it makes any sense, given Josephus' background. He literally devoted years of his life to becoming intimately familiar with the various extant forms of Judaism in the area, yet somehow, he completely fails to mention a new and rapidly growing sect based on a supposed messiah?