Dr Hynek states that Nickel burns "green" when in actuality it burns silver-white. Copper burns green and so do boron, thallium and antimony among others, but not nickel.
In the scene with the nuclear siren scare, the two soldiers in the weapons carrier vehicle attempt to radio for help. Although it's the early 1950s, they are seen using a modern, current issue US Army handset, not in existence until decades after the show takes place.
When Dr. Hynek explains how his photo equipment works to Cpt Quinn, referencing azimuth, Cpt Quinn mockingly repeats the word, as if he were a knuckle dragging moron. Since Quinn is supposedly a pilot, he should know exactly what the word means and understand the context in which it should be used.