The point of the editorial was that failure to report, when the law requires reporting, constitutes willful misconduct. Valuable safety information is lost forever when controllers fail to report information that may prevent a future accident and great loss of life. Heavy penalties are usually imposed on pilots and taxpayers who fail to make required reports, but, in most cases, when ATC controllers fail to report, there is no penalty. They simply get the same additional training they would have, had they reported as required. Libel is the printed defamation of another.
Truth is always a complete defense to a charge of libel.
That has been true since the John Peter Zenger trial in 1735. It is one of the first cases to establish that juries could judge the law as well as the facts of the case. It also was one of the first examples of jury nullification. The jury found Zenger innocent even though the law said he had committed seditious libel simply by printing criticisms of Governor William Cosby. Prior to that trial, the law did not recognize truth as a defense against libel.