Even though the promise was verbal and not in writing and even though the identity of the campaign manager was a matter of public interest, such a promise of confidentiality was determined by the United States Supreme Court to be legally enforceable.  Don’t promise a source confidentiality on your own behalf or that of anyone else, unless you and your colleagues are all prepared to keep that promise.

Do not agree to a freelance contract that makes you responsible for someone else’s legal expenses and liability.  See whether the publisher will agree to a “best efforts” clause instead.

Be very careful about any promises or representations you make to any subject or source in the course of news gathering.  Such promises can be legally binding.  You don’t want to be restricted in what you can and can’t report to your audience.  Even if you really believe a story is going to turn out to be positive, do not promise that outcome.  It’s much wiser to keep your mind and options open and indicate that you’re making no prejudgments prior to completion of your information gathering and posting or other form of publication.  Also, if you’re covering an issue or event or subject and your goal is to inform some segment of the public, while fact checking is always a good idea, don’t promise or give your subject the opportunity to review your story or manipulate your content prior to publication.

Before you publish any information possibly covered under a non-disclosure commitment, you’d better take a look at what you signed.  If you’re unsure whether the information you plan to publish is covered under the agreement or you are certain it is but wish to publish the information anyway, better to run the specifics by a lawyer in advance.  You may be perfectly within your rights to publish and maybe there’s even a whistleblower law that will support you in an effort to disclose wrongdoing.  Still, a quick consultation will cost a small fraction of the costs you’re likely to incur should you become a defendant in a lawsuit.