Maybe not a bad thing ....
since it'll tie them up for years, keeping them from other vulnerable people.
IANAL but even I can see this is a stretch ... especially in a population that was already headed towards the grave anyway.
Even if you can prove a person who died from breast cancer (and that'll be fun, as there are myriad ways to die from cancer that don't say "cancer" on the death certificate) you are still left having to show that had they received a call for screening AND they had responded (remember that 29% non attendance) AND the screening had picked up their cancer (remember false negatives) AND that result had triggered a course of treatment (bearing in mind what was available at the time) AND that course of treatment had been successful (because all treatments have a failure rate) THEN you might just be in with a chance.
To be honest I'm more enraged about the casual admission that some poor innocent was blown to pieces by a trigger happy RAF ... pity his family.