I work in a school district and things are not always so black & white.
For one, the mother chose to wear a shirt with an AK-47 on it for their photo op with the van that was gifted to them. Gun rights aside, the tone of this situation would lead most to chose more appropriate attire. When assessing situations like these, you need to take all the subtle character hints you can find. I, for one, think she may have trouble with responsible decision making. Then again, she may just have an irreverently wry sense of humor... but still, it doesn't help her case.
Situation A: The child is a good student and well-behaved, but is often late for school. Everything the mother says is true, and the family is having health and car issues.
Resolution A: The school needs to be understanding, talk to the parents, and help them with the transportation problem (e.g. help to find another parent that lives near them and would be willing to carpool her child)
Situation B: The student has behavioral issues and his tardiness has been an ongoing problem. The school has spoken with the parents, but they are argumentative and spend most of their time blaming the school and teachers while not honestly addressing any issues that may need to addressed in their home. They've had a long string of excuses, and the child's behavior often mirrors their own.
Resolution B: The school needs to be considerate of the fact that the child comes from a home with poor discipline and bad influence. The school then needs to come up with a course of action that both addresses the bad behavior with appropriate discipline, but also tracks the student's intent and progress, fostering an environment that allows the student the opportunity to make good decisions. Once they're at a point where his only breaks from policy are a direct result of his parents' bad decisions and not his own, the school should become appropriately lenient and understanding.
Situations C-Z: The rest of the gray areas of this story.
Keep in mind that the school is in the position of enforcing rules for all the students equally and fairly. Openly exempting certain kids from rules without being able to fully explain why someone gets a pass (for privacy's sake) is very tricky business. It's an intricate balancing act.