Warrantless spying should be illegal full stop. Let alone installing equipment on someone's land or cutting down their trees. I hope the government agency responsible for this is soundly reprimanded in court.
They'll just get told to pay $25 for the lost value of wood on that tree branch.
And if a pleb logged a few feet over the property line and that was a government tree you could bet they'd be going after him for some insane fantasy value of it.