Did you miss the part of where, if he’s a due paying owner in that neighborhood, he is part of the HOA.
One thing we don’t know for sure is if he neighborhood HOA has rule against fishing, which in Florida they likely do, I used my Florida Neighborhood as an example, we have signs in the community lake prohibiting fishing perhaps you missed that as well, not just myself, but everyone in the neighborhood has the right to tell someone fishing to stop, if for no other reason than liability issues.
As I’ve stated the gun part was stupid and likely criminal. You can’t seem to separate legitimate property rights issues and HOA rules from the fact the guy was an idiot.
And that means zip zero. Did you miss the part where this mental case was hauled off to jail and charged with multiple felonies? ☺