I don't think his team are. He may not have done all of the things Amber says but I think most people can be certain some level of physical abuse took place on both sides. Other abusive behaviour took place too on both sides.
They only need to think one incident took place to make a judgement in favour of Amber. I think they can. Imo That's why Camille said you can't just believe one incident took place you have to believe they all did. Which isn't true. But she wanted to plant in the jury's mind that they have to believe it all or nothing. Knowing that it's likely they can't believe everything Amber says.
Btw JD has also lied on the stand. Saying he is a southern gentleman, saying he only had minimal champagne before the Boston flight, saying only Amber uses the word monster about him, that he's in control of his drug/ drink use and doesn't have blackouts and violent behaviour when on binges. Saying he didn't kick her on the Boston flight.
I also personally think he is lying about how his finger got cut off. I believe the hand surgeon that a glass bottle being thrown is not consistent with his injury and there are several references to him saying he cut it off himself. Plus he changed his story.
They both lie.