Private property is private property. The police had no right to go on his land and seize his property considering no laws were broken.
Section 285b of Title 2 of the US Code. Read it then explain to me how the man was in dire distress with etreme danger to life or property. If you can successfully do that, then I will admit that no laws were broken. The fact is, the man was in flagrant violation of the US Code. This DA, the cops, nor anybody else knew this, but that changes nothing.
But hey, I'll play. Even a shitty attorney could make a case for disturbing the peace with this one. If the peace was truly disturbed, then the police had every right within the law to seize the flag, just as they would alcohol at a party that was out of hand.
He was protesting the government not allowing him to conduct his business.
What peace was disturbed? They claimed that it could upset some of the other veterans that would being in the parade. Also, if people are getting drunk and being rowdy then they are violating other people's rights. Flying a flag upside down has no such effect.
How does the bolded part demonstrate and extreme danger to life or property? I'll answer that for you. It doesn't. A liquor license is a privelage, just as a Driver's license, CDL, hunting, fishing, or medical license is a privelage. They are not rights, so the government violated no rights by denying the license.
If people are offended by the flag flying upside down, then it would be a disturbance of the peace. If it upsets people, especially on the holiest of holy days in our nations history, then it constitutues a disturbance. They let him fly it on Friday. He was back to flying it on Sunday. I really think the man is making a mountain out of mole hill here.