In reply to GravitySucks:
> Not seen the film but heard a review on R4, I think the significant fact was supposed to be that the husband was still named as the deceased 'next of kin' 45 years later. Not sure if that helps to explain the reaction or not
Not really. He explains that he was recorded as that because they had pretended to be married at the time in order to stay at hotels which seems and seemed reasonable to me.
(That is apparent within the first ten minutes of the film so it's not a "spoiler")