While Colonel Wilma Deering is saving Buck Rogers from the Draconian flagship, the left side of her flight helmet reads "Cool Deering" in one shot and is blank in all the rest.
When Captain Buck Rogers fights Tigerman in the launch bay of the Draconian flagship, the actor is very dissimilar from the one in the rest of the film.
When Buck is in the ruins of Chicago and the graveyard, the likelihood of the signs in the streets and the gravestones still being legible after 450 years is nil. Weathering would have totally erased the words from the signs by then.
Although two starfighters ascend from Earth to intercept Buck's ship, we see four blips representing four starfighters on the "big screen" in the control room.