The pole was obviously on public property.
I'm not sure of the specific law, but they probably even have ownership rights of the pole now. They gave the people the option to come down and get it back too.
Really, I don't see how this is different from somebody smoking in a restaurant and then refusing to leave or something.
Act like a jerk when you are breaking the law and somebody decides to compromise with you, and they'll probably get peeved and make you cross your Ts and dot your Is.
Does anyone actually think the government (or the moderators in this example) would stop and go, "OH, you're right. Since I missed that other guy, I'll just ignore the law and forget I saw your basketball pole/unban you."?
That excuse gets quite old.