That headline is justified.The NATS system failed. Dodgy French data or not this was a failing of a NATS system. We know it failed, the investigation will need to explain why but far more important is which of the following three cases applies.
Either:
That failure was unforeseen, in my experience unlikely for NAS for which there are precursor failures, and I would hope unlikely for the other systems in the thread given the obvious possibility, however rare, of common software failure.
The failure was foreseen but the impact was not correctly assessed
The failure was foreseen and the impact correctly assessed but the controls expected to contain such a failure didn't work as expected.
It's always a bit tricky for systems like this because of the interaction between flow regulation to maintain safety and the business impact that results from that regulation.