Either the injured person or someone acting on his behalf can make the entry. The injured person is obliged to inform the employer of the injury (which can be by writing it in the book but can be by any other method) and the employer is obliged to make the book accessible. There's nothing in the regs that places an obligation on anyone to fill the book in.

I was taught on my NGC that the reporting is heirachical i.e. The injured party The person giving first aid The injured parties manager I've always done it this way. Rich