I don't think he meant that he supports the whole group. The name of the group is the most deceptive part, which makes me think that he doesn't realize that BLM is about way more than black lives

I mean, they named it Black Lives Matter for a reason. That way if you disagree, you look racist. He probably doesn't want to say anything that's going to rub anyone the wrong way after what he's been through. He also mentioned not being very political, which makes me think that he agrees with the phrase "Black Lives Matter" and not the group "Black Lives Matter"