The incident has come to light because 'Andrew' has decided, for whatever reason (especially as he claims he wants to have a quiet retirement), to go public about a report he collated at the request of NATS.
The report was probably restricted (a standard procedure for large companies)... therefore 'Andrew' has broken his agreement when he signed up to the Official Secrets Act. Sound far fetched? Well it isn't, its fact.
Another fact is that the Public are the single biggest shareholder in NATS and the issue is of public interest. By all means, scurry away and have a secretive huddle in the corner but that isn't exactly in keeping with the open and honest culture you are trying to portray.