From what I've seen of him, he's always being disrespectful of other fighters. I get that this a business and he's out there trying to create a buzz for his son but you can do that without sounding like douchebag.
The minute he said he thought his son definitely won the Lomachenko fight and there's no reason to have a rematch, he sealed the fate of his son's career. Devon will never improve beyond his current level with his dad being a delusional yes man.