Welcome to Florida. The ignorance in the school system here is so broad it's astounding. Like the OP stated, the school bus can be late for whatever reason and it's not a problem. The last time my son's bus was late it was because the driver overslept. None of my children has ever served a detention, nor will they for anything so trivial. I would have just taken my child home and have them been absent rather than serve their detention. Absolutely ridiculous.