Character mistake: When Ginnifer Goodwin leaves the supermarket to go the parking garage, the green sign says 1 hour parking Customer's Only. It should say Customers Only, without the apostrophe.
Chapter 9: The Marshal - S2-E1
Character mistake: Cobb Vanth says that he's never seen anything but the dragon's head and had no idea about the size of the dragon...but at the beginning of the episode we could see the beast pass through town (conveniently right in the main road without damaging anything else) and its enormous lengthy body was perfectly noticeable. (00:31:20)
Character mistake: Batwoman does everything she can to rescue the elevator falling down after the villain detonates the bomb, but does nothing for the second one Tommy blows up to make her lose her footing when she is vulnerable. There is no message from Luke telling her anything, and she is not shown having a HUD with thermal readings or something like that, so there is simply no reason why she would risk everything to stop one elevator and completely ignore the fate of the next one which could be full of civilians as well.
When in Rome - S1-E3
Character mistake: Nobody in this scene knows how to dance the tango that is playing. (00:16:35)
Character mistake: When Harlan Edwards collapses and Dr. Arcane tells them to clear his airway, one of the other doctors addresses her as "Dr. Cane."
Character mistake: At the police station when Damien Asante is reading the information on the computer about the hit and run, he says "On February 25, 2015 Christy Markus and her son were struck by a car. The driver kept going." If you look at the computer screen, the date of incident says February 25, 2018. (00:30:00)
Character mistake: Shaun says that the underground facility is "built like a bunker", but the single missile they dodged just created a huge hole a moment earlier. (00:11:40)
Character mistake: Captain Quinn expresses not knowing what an "azimuth" is. The man is a pilot. What pilot would have never heard of an azimuth? (00:13:50)
In the Waiting Room of Estranged Spouses - S2-E6
Character mistake: The former Marine, Spenser, refers to himself as a soldier. A Marine would never do that.
Character mistake: When meeting with the network exec in the bar in the opening scene, Bradley orders bourbon on the rocks. When her drink comes it is without ice.
Character mistake: The date on Louise's plane ticket to London is listed as "Thursday 16 February 2017", but the month "February" is missing the U, misspelling it as "Febrary." (00:15:56)
Character mistake: The Captain's medal ribbon bar is sewn onto his uniform back to front, with the 1939-45 Star on his left and the 1939-45 War Medal on his right.
Suggested correction: This is explained in the final episode, as he took somebody else's medal ribbon bar in order to get into an event only open to "decorated" officers and hurriedly put it on the wrong way round. However, this is also a mistake. Although the Captain never left Britain, he would still be entitled to the War Medal and Defence Medal, so would legitimately have two of the ribbons he wears. And having campaign medals does not make one "decorated" in any case.
Character mistake: In Season 5, Episode 4 ("The Heart Attack Boys"), Abishola twice gives Christina an injection without swabbing her skin with alcohol. Abishola is an RN and would never make that mistake.