At one point in life, I was full of excuses. I felt that people would be more forgiving if they understood why something happened. While a short explanation may be in order for some situations, excuses are never a good idea.
While doing business in my promotional advertising company, I recall a few instances when there was an issue with an order. While you always want to put out fires and reflect later, no one really cares about why something went wrong when they are in need. In fact, you lose a lot of respect when you make excuses for a “mess up”.
The key is to take full responsibility, make it right based on what the customer wants and then do just that. Think about your next oh-oh and how you might be able to turn it into an opportunity.