Despite Killmonger being referred to as "Lieutenant," giving him a pay grade of O-2 (Lieutenant, Junior Grade) or O-3 (Lieutenant), his shoulder boards on his white dress uniform display the insignia of a four star Admiral, pay grade O-10.
Killmonger was a Navy SEAL, yet the insignia on his uniform bears no resemblance to ANY Navy insignia, much less the Trident representative of Navy SEALs.
Killmonger's carbine is not equipped with an optic or iron sights, leaving him with no discernible way to aim it.
Killmonger admonishes Rhodey for betraying his people by working for the US Air Force, yet Killmonger himself is a Navy SEAL.