There are no absolutes in business. You make commitments, put yourself on the line, and then see how you did. Unless you complete that feedback loop and hold everyone’s feet to the fire, nothing really counts.
However, before reprimanding employees for making mistakes, you need to hold yourself accountable. You must acknowledge your own mistakes before pointing the finger. While you may think this will make you look vulnerable in front of your employees, it will often have the opposite effect. You want to show your employees that you are fearless (but not without fault) and this will promote respect as well as a positive work environment where everyone is in it together!