Factual error: There is a periodic table shown in the background of the lab, showing an accurate periodic table as of now. During 1945, at least 21 elements had not been discovered. (00:17:40)
Factual error: 1-1 A couple of spelling errors. A "community center" in Ceylon, a British colony, using the American instead of the British spelling. And Columbo listed as the capital of Ceylon; it's Colombo.
Factual error: The Marine Colonel in Supergirl played by Eddie McClintock spends all of his time wearing Marine Officer's Dress Blue Bravos. Marine Dress Blues are ceremonial uniforms. On rare occasions, the Charlies or Deltas (no coat) may be worn as a work uniforms (the primary exception to this rareness being recruiters). The full uniform is certainly not worn for day to day work in the field.
Factual error: At an eating area, a collector shows a man a computer screen with his daughter in real time and has her call him. She then speaks in the phone and you can see her lips and actions lining up perfectly with the words he is hearing. It would not be this perfectly in sink even in the most optimal of conditions. There is a slight delay between the video from the camera and sending that to the computer being shown. And then there is also a slight delay of the phone single traveling through one phone to the other. These would not line up right and so the father would not see the lips moving exactly with what he hears his daughter saying over the phone.
Factual error: Jessica receives a call from a prisoner at a State Institution. It shows up on her cell phone as "Unknown." All calls from prisoners are collect calls, and the receiver is asked if they will accept the charges. (00:41:20)
Factual error: Every episode in the first half of this series begins with the same phrase and the same map of the Italian peninsula. Said map though misspells, in a very Japanese way, the north-eastern city of Trento, wrongly appearing as Torento. (00:00:01)