TTM _ there is no way that your DHs boss can sack him - he just ain't senior enough and doesn't have the clout. As long as the pay arrives in the bank each month, your DH is still employed by the RN. Is this WO your DHs boss AND his Divisional Officer, or just his boss? If the former, your DH needs to take this higher, and if the latter, then he needs to go and see his DO PDQ to get it sorted. If the DO then doesn't do his job - go higher again. The WO still takes a dump like the rest of us, and is only a WO - not God.
If the WO is doing this to to other people as well, then those who run the department will be aware, and biding their time, and writing their reports to boot. They will also want to be aware of both sides of the story. The WO is NOT untouchable, quite the reverse, and should be aware of that.
Don't quite understand the comment about your DH having a family being the root cause of the problem. They are paid to do a job, and have to do it irrespective of family commitments most of the time. I think they try to help where they can, but it isn't always possible. Don't stress yourself worrying about it, your DH only has 5 months to go...will he be doing resettlement courses first? If so, then he won't have much longer to go with this guy. If he lets the WO see that he is wound up, it will get worse, so he needs to say 'Yes WO, no WO, 3 bags full WO' and ensure that he is present, correct, and doing his job to perfection, then the WO can't pick on him; play him at his own game, which will really p**s him off.
We all get crap bosses, irrespective of rank, job, Armed Forces or Civvy Street and sometimes unfortunately, you just have to suck it up and learn the lessons of how not to treat other people.