Nuisance is in the eye of the beholder. He knew what his rights are and he was asking for them to be respected. The SRO didn't care what the law said, he thought that the school rules superseded it. They do not.
The dad seems calm and collected. The officer seems to be pissed at the fact that his authority is being questioned (superseded even?) by the dad. The entire six-ish minute exchange seems surreal and bizarre, to be honest.
Help me understand here, why would there be a rule prohibiting parents from walking their kids to/from school? No pavements? Very busy roads? Precedent of some sort?
Is there a rational explanation for why the rules would be the way they are? I have no idea really. It doesn't make any sense to me either.