Some unscrupulous salesperson would promise anything to the client to close the deal. They sometimes make promises and give assurances that are unfulfilled, but who cares. In most companies there is a complete disconnect between the guys who markets/promotes the product, sell it, deliver the service, maintain it and take the feedback. Everybody is given a target which is impossible to meet and the guys who live on commission often live paycheck to paycheck.
However do all this justify the shortcuts people take to close the deal? Giving false assurances to business associates is often the preferred Band-Aid used to postpone the inevitable anger and escalations, but does it solve anything?
What I have often seen is that it only tarnishes your credibility and the value of your words and assessments. The world is increasingly becoming connected and everything is being archived & recorded. Your honesty, promptness and straight forward lying of facts, no matter how bad, will only add to your credibility. After all a timely warning will give your associates ample time to take alternative measures and do damage control… rather for waiting for a miracle.
You might change your company in a couple of years, but the world will always remember your face. Your deceit today might not save the situation, but will surely damage your reputation.