TRMS and some other US coverage of the recent tragedy in France keeps referring to one of the person's still being searched for as the girlfriend or partner of one of the deceased. I thought that was kind of ridiculous, and concealed an important aspect of this group: they feel so strongly negative about the civil government that they refused to go through the civil ceremony required to make their marriage valid, and only had a religious ceremony. That is a really important action, one that tells you a lot about the kind of people they are and what sort of authority they respect and how comprehensively they want to separate themselves from authority they do not respect.
For the first time in a while, I checked in on NRC's website, and boy, they conceal the issue from the opposite direction: they just straightforwardly recognize the couple as having been married, using words like, "weduwe" and "echtgenote" (the man is now dead).
I think if you aren't going to offer up the details each and every time, I'd prefer to go with recognizing the marriage. But I also recognize that if you're part of a current fight for civil recognition of marriage as the recognition that matters, then when somebody else blows that civil recognition off, well, treat the relationship as Not Serious too.