Man with a shotgun and a Green lane, Laning, byway confrontation

Is this ok to walk down a public right of way with a shotgun uncovered? i dont know and would appreciate your thoughts.
This particular green lane is open to solo motorcycles all year.
This sign on this link shows no motor vehicles, if the sign has dates it could be vehicles are allowed outside the dates on the sign.
https://assets.digital.cabinet-office.gov.uk/media/55b9f4d840f0b6151f00001b/sign-giving-order-no-motor-vehicles.jpg
This is the sign at the start of this lane before we encountered the man with the shotgun.
This sign shows no motor vehicles EXCEPT solo motorcycles
http://www.drivingtesttips.biz/images/no-vehicles-except-motorbikes.jpg
This website is awesome and has may of the signs shown as real examples.
http://www.geograph.org.uk/article/British-Road-Signs-2002/6
(© Copyright JThomas, Road Engineer, Alan Murray-Rust, Chris Downer, David Dixon, Hugh Venables, Malc McDonald, David Hawgood, M J Richardson, Albert Bridge, Stephen Craven, Jaggery, Adrian S Pye, Nigel Cox, Robin Stott, David P Howard, Maigheach-gheal, Christine Johnstone, Chris Heaton, Graham Horn and Tiger; licensed for re-use under a Creative Commons Licence. http://creativecommons.org/licenses/by-sa/2.0/ )
Please let me know your thoughts and comments.