Good for you OP. That 24 hour policy is for the parents who keep their kids home and nurse them back to health without a Dr's in-put. If you bring your child to an MD and that MD determines you child can go back to school because whatever it is isn't contagious they had zero reason to turn you away. I think you were totally treated unfairly and deserve an apology, you probably won't get one because people are just rude that way, but you deserve it.
This is not true at all and a bit ridiculous, IMHO. Many doctors make mistakes - I won't tell you about the horrible doctor at Centra Care Clinic on SR 535 while @ WDW who misdiagnosed our toddler. He assured us it was ok to go back to parks - thank goodness we didn't listen to him as she was very ill. She would have made many other children sick... We were ambulanced to Arnold Palmer's Children's Hospital a few days later! Doctors are regular people with more medical training - they are not infallible, so a doctor's note should not override the 24 hour fever free policy at all.
We practice 48 hours here at home and hubby and I are working professionals, and we do it as our kids (especially todller who has ear tubes and asthma) will spike fevers at 30 or 36 hours, despite being fever free for 24 hours. Illness is tricky, and when you have kids playing and working together in very close quarters, things spread, and that is the reason for the 24 hour fever free rule.
If you have kids, you have to be ready to deal with illness. I know some jobs are tough to leave, but then as parents, it is our duty and responsibility to make whatever plans are necessary to get the sick child out of the company of others.
Tiger