He didn't help her either and tried to justify it, remember? Not really truly sorry. Never really thought about the pain his people inflicted. He was there for it all. He helped them. He fought off people who might have freed her. He knew what they were doing and did not really think they were wrong; he's just sorry that they were caught...
Also, maybe Hachi was never able to actively bully Nami and the villagers? He's such an idiot I could easily see him failing at it and being bullied by Nami instead