How have the courts treated a libel action brought by a journalist who recklessly published an untrue defamatory statement?

The question then centred on whether carelessness was to be equated with not holding an honest belief in the truth of the statement. That very point was addressed by Lord Diplock in the passage in Horrocks v. Lowe immediately following the passage which I have already quoted, at p. 669: If he publishes untrue defamatory matter recklessly, without considering or caring whether it be true or not, he is in this, as in other branches of the law, treated as if he knew it to be false. But indifference to the truth of what he publishes is not to be equated with carelessness, impulsiveness or irrationality in arriving at a positive belief that it is true. The freedom of speech protected by the law of qualified privilege may be availed by all sorts and conditions of men. In affording to them immunity from suit if they have acted in good faith in compliance with a legal or moral duty or in protection of a legitimate interest the law must take them as it finds them. In ordinary life it is rare indeed for people to form their beliefs by a process of logical deduction from facts ascertained by a rigorous search for all available evidence and a judicious assessment of its probative value.