They should have at least remained silent. By issuing grossly misleading denials they look silly and dishonest. And yes, cowardly.
Had they said, "We do not comment on matters of national security," such would have been honest, careful, and truthful and it would have been darned hard to prosecute them or put them at risk for effectively revealing that the press was right.
Had they said, "We do not comment on matters of national security," such would have been honest, careful, and truthful and it would have been darned hard to prosecute them or put them at risk for effectively revealing that the press was right.