Mattis is a good man... don’t have to agree with him on Trump.
I think his comments ought to be taken in context of the venue in which they were offered. In other words, he was joking.
I have zero grief with Mattis. He showed class when he left the administration on principle, and he did it the right way. He wrote a book, got it published, went on the obligatory book tour and, despite all the people wanting him to say bad things about Trump, he didn’t.
As far as I’m concerned, he’s a class act.