It's dishonest not to honor your verbal commitments.
James, the CEO of an up and coming tech firm, has had a verbal contract with a programmer for years.
James wants to hire a more talented programmer.
James offers his old programmer a generous severance package and hires the new guy.
James fires his old programmer without severance and hires a new guy.
James is able to part ways with his ex-employee with little friction.
James gains a reputation in the industry for being untrustworthy.