In the five years I spent at Top Cow, and even the ensuing months entering the freelance world whilst straddling both sides of the desk, I've seen almost everything. No, no one ever pulled a fast one like fake tracking numbers or empty boxes, but I've heard the entire gamut when it comes to excuses for why things don't coincide with the initially agreed upon deadlines.
One of the things I've been careful to remember, and hopefully succeeding in doing, is that as a freelancer you are your brand. Your company is you, represented not only by your work, but by your actions. On your personal projects you can screw up as much as you want. You're the only one that suffers. When you're working for someone else, there are no excuses.
And yet, things happen. You mess up, a crisis can't be averted, etc. Read this article tonight about how to handle missed deadlines, and I think plenty of comic PROFESSIONALS and freelancers in other industries would be wise to brush up on their client-freelancer etiquette in the event they find themselves missing a deadline for any reason.
Sometimes just these simple acts go a long way.