@bam52468,
It was not your Mom's choice to pay for the ketchup damage. She has a legal obligation to pay.
It doesn't matter if you do it at McD or a fancy restaurant. You are old enough to know that.
It doesn't matter that your brother started it. You joined in and you should have known better.
You majorly embarrassed your mom. You don't seem to care much about that. She minorly embarrassed you. No one there took her words literally. Your mom deserved a good freak out. You not at all.
Have you applied for a job at McDonald's yet?