Revealing mistake: When the Nazi doctor starts to torture Solo in the electric chair, he turns off all lights in the room except for a single dim light bulb over Solo's head; so, we know that the background is uniformly dark. Moments later, when Ilya comes to the rescue, a lighted control room appears behind the doctor, off to one side. After they strap the Nazi doctor into the electric chair, there is now a lighted control room directly behind the chair.
The Man from U.N.C.L.E. (2015)
1 revealing mistake
Directed by: Guy Ritchie
Starring: Henry Cavill, Alicia Vikander, Armie Hammer, Elizabeth Debicki
Character mistake: When Gaby's car becomes wedged between two buildings, she says, "Good plan. All we have to do is get over two twenty-foot walls and a minefield." While minimal backstory is given, I think it reasonable to assume that she has lived in what was East Germany all her life. It is thus highly unlikely that she would express a measurement in English units (being bilingual doesn't mean you automatically convert measurements). She would have said something like "six meters."
Napoleon Solo: [Telling Kuryakin to let himself get mugged] Take it like a pussy.
Illya Kuryakin: This is not the Russian way.