[jjgreen]

I'd agree with your

Like all computer system, you cannot remove all risk from the system. But you can reduce it significantly ...

so that we can both agree that the article's statement

It lets research scientists dig into 58m NHS health records – while seemingly doing the impossible and completely preserving patient privacy in the process.

is so much tosh. That being the case, I do not consent to my medical records being used in this way, not that my consent will be sought. "Do no harm" my arse.