Just want to chime in and say that, as best I can tell, in Nebraska, vehicular gun mounts/racks are legal, I cannot find any law specifically mandating or banning or regulating them, beyond uh...
https://nebraskalegislature.gov/laws/statutes.php?statute=28-1204.04
Which says that if you're in a school zone, your vehicular gun must be unloaded and in a locked gun mount within the vehicle.
The most relevant law I can find says that shotguns in a vehicle can't be loaded, while said vehicle is on the highway.
https://nebraskalegislature.gov/laws/statutes.php?statute=37-522
Class III Misdemeanor.
There does not appear to be a law that just says 'any gun in a vehicle must be unloaded', full stop.
So... if the driver was never on the highway...
No actual crime, as far as I can tell.
Maybe I missed something?
https://giffords.org/lawcenter/state-laws/guns-in-vehicles-in-nebraska/
(Not that I think that is any kind of a sane approach to gun law, nor was this a sane demonstration of gun handling practices... just trying to lay out the facts as best as I can.)