All guns can jam or misfire. Thats why we clean them incessently lol
Indeed, though in this case it seemed as a direct result of the mechanism that ejects the spent cartridges (excuse me, I know basically nothing about guns, not part of my culture) the cartridge basically got stuck, preventing further firing. I don't think the double-barrel has a mechanism like that, it seems fairly simplistic.
I expect that the adjustment to larger bean-bag rounds probably makes jams of that kind more likely.
I did some research and it seems there are plenty of custom sawn-off holsters, so it should be fairly easy for my character to access the weapon and then holster it when he needs to access other gear.