Our gullibility doesn't excuse the misleading, but to your point you shouldn't factor in vague and unenforceable promises when negotiating or settling a contract.

SD is there to manage Flight Ops. He answers to his superiors, and his first job is to back them up. Doesn't make him mean, or cruel, or weird. If the choice is between expanding a little credibility to support the mission, or to gain more trust at the expense of some votes, pragmatism invariably yields a sales job.