I think you are missing the point, the wider point contained in the judge's logic. If the fool in question had refused to do his job, the job for which he was hired, that should have been reason enough for dismissal. But Laws went much further than that. The logic of his decision undermines the basis for any religious or - as I understand it - moral objection to the "legal obligations" that concern you so much.

"We have no conscription in the UK, so no-one is obliged to serve in the armed forces or go to war. It would require an Act of Parliament to bring in such conscription and this act would probably provide for conscientious objectors"

What would be the basis for conscientious objectors? Any reason put forward for refusal to serve would necessarily be subjective.