This is a problem. If the SOP's say he should take it and he doesn't then there is a breakdown in the system that needs to be resolved. Now you have been put in a position where you may get into trouble for just trying to do your job because he isn't doing his (I am assuming this 'cos I don't know what the requirement is in your company). Strategies you can utilise are:
1. Talk to the senior cabin crew in your team
2. Submit a report anonymously if you company has such a facility
3. Talk to your safety/security department or the pilot who is involved in safety/security/CRM issues. I am sure he will back you up.
As you know, certain documents are required to be retained after a flight for up to afew years for audit purposes etc. This should be resolved. Good luck!