Jack's business relationship with his only client turns personal while Olivia struggles to find any clients at all.

Hiscox Commentary on Small Business Insurance
Getting past the question of Jack's possibly faulty moral compass, what are his obligations to Scarlett and Olivia as clients? He's certainly misrepresented Scarlett's opinions of Olivia in his call to Mashable, at the very least.

Is this something you could see her filing suit over? What if it was something less scandalous? He implied she had a new book deal in the works, when she'd only discussed one with a publisher. There's really no such thing as "off the record" with the media, and Jack is now speaking on behalf of both clients.

This is another case where professional liability insurance (errors and omissions insurance) could help protect him from mistakes or unsatisfied clients if things go wrong. Try as hard as he might, things might not work out, and the legal costs of defending a lawsuit could sink his business before it really gets started.

What if he hadn't landed the article opportunity with Mashable for Olivia? She's just starting out too, and she spent some of her precious savings/severance on his services. Could she sue him for failure to deliver? I know they're friends, but all's fair in love and $500,000 mystery business competitions.

Are you in the business of giving advice? If so, make sure your business is protected from the specific risks you face on a daily basis.