I sense Chiwetel's character had something personal against Salt

It seemed like he really hated her. He never tried to give the benefit of the doubt, he shot at her and of course he very unprofessionally punched her while she was tied up at the end. Is he jealous of her? Is there some sort of sexual tension there? Did she turn him down in the past or does he have a crush that he can't express? His whole obsession with destroying her was weird.