I absolutely understand how this affected you and your daughter! I also understand that when things happen that really trigger us, there is usually a reason that we haven't considered because we are so stressed over it. That's why I tried to interject what that reason might be.
I'm glad you were able to find some calm about it all and that you had a good response from the school regarding this issue. Mistakes and missteps happen in life and it's communication that can fix those things! Good for you!