@jdox0776,
Is there a student handbook? Most schools have these -you should be able to find it online. In the handbook they should state how they are supposed to handle any sort of injury - whether minor or more serious.
I personally think they went overboard reporting you for one bruise. I would have calls daily if this were the case, as my children have lots of bruises - from playing sports. It is normal for a child to get a bruise although several bruises should arise a question. Did they question your child at all? I wonder if she said something (not meaning anything but could have resulted in them raising an alarm) -
On the other thing where your child came home with a bandaid -- the nurse should have called you - even for small things so you are aware. I have received calls from the school before when my daughter fell or was hurt even it is was minor. In part, I think the school tries to cover themself.
But I would read the handbook first cause then you can call the school and say it says here in the handbook that if a child is injured even whatever it is. And then just state the facts, my daughter came home with a bandaid on her chin--could someone get back to me and let me know when happened and in the future, could I please receive notification so I am not worried?
If there is nothing in the handbook or no handbook, then I would suggest calling. Try to handle it without getting too angry or upset and be polite --- more trying to get info. Say along the lines, my daughter had a bandaid --- could you let me know what happened? Then ask what their policy typically is -- you could also ask if she is injured in any way could they give you call before she comes home so you are aware? I worry if you come across too angry or upset, they will think it is strictly because they reported you and you are trying to get back at them.