Factual error: When Diana first brings Steve into the DC Metro, the modern-day signage visible inside L'Enfant Plaza Station is not era-appropriate to 1984. It includes markers for the Green Line (opened in 1991) and Silver Line (opened in 2014), and all markers are shown with printed abbreviations, which were not added until the Silver Line opened. (00:57:49)
Factual error: As his secretary Raquel tried to tell him, Max has his kid with him because he gets to see him on weekends, and that's 'his weekend'. Good but...it is not the weekend. This is Wonder Woman 1984, and the robbery happened on July 1st, Sunday, and this scene happens two days after that. Maxwell's "weekend" is happening on a Tuesday. (00:36:25)
Factual error: As Barbara Minerva is introduced together with her comical inability to walk properly on heels, she passes by "Henry" the elephant at the Smithsonian. But the elephant is on the newly designed infographic podium of our present day, inaugurated in 2015. In 1984 he'd have been on a simpler, differently designed stand. (00:20:10)
Factual error: The F111 that they pilfer from the Smithsonian doesn't carry enough fuel to make it from DC to Cairo without refuelling; also the aircraft on display at the Smithsonian are not fuelled or flight ready.
Factual error: When Diana is about to land on the remote base, a CRAM fires at her and attempts to take her down. The CRAM was not developed until 2006.
Factual error: When Wonder Woman and Steve Trevor are walking out at night near the Washington monument, a plane passes overhead. A TWA Airlines A320 or A319, which Steve looks at and says "amazing." Moments before that, Wonder Woman has confirmed that the year is 1984. The only problem is, a TWA never operated that kind of airplane and the A320/A319 didn't even exist in 1984. (00:47:43)
Factual error: Diana tells Steve to sum up Barbara's report that the stone appeared in places that all have something in common; "Their civilization collapsed catastrophically, without a trace as to why." That's just ridiculous; one could even argue it could apply to the Maya, who did suffer a sharp decline historians have not reached consensus on, or the Kingdom of Kush's, due to not a great abundance of historical sources, but Carthage? And the Roman Empire had been in a crisis for centuries and it is far from being some mystical overnight disappearance. (01:27:50)
Factual error: Diana conjures a shield of invisibility for the jet, but must have also summoned a sound-dampening spell, since the two are comfortably chatting without a helmet and / or usage of the intercom. (01:08:20)
Factual error: The metro scene shows signs for the green and yellow lines. The green line didn't open until 1991. The scene also showed an electronic sign that shows the time until the next train. These weren't installed until much later than 1984. (00:57:50)
Factual error: Diana decides to attend the party Lord invited her to. The music played as she makes her way through the various sleazeballs is "Welcome to the Pleasuredome" from Frankie Goes to Hollywood's eponymous album, which was released in 1984 yes, but just on October 29th, and almost a whole year later as a single. The movie takes places around 4th of July. (00:41:05)
Factual error: Diana is having a romantic walk with the newfound Steve by the Reflecting Pool, walking towards the Lincoln Memorial. Behind them there's the imposing shape of the Washington monument, but also lit in the night are the columns of the World War II memorial, which was built entirely in the new millennium. (00:46:50)
Factual error: The plane that Diana and Steve steal from the Smithsonian appears to be a mix of the fuselage, wings and tail of a Panavia Tornado F3 and the cockpit of an F-111 Aardvark. This class of aircraft has a maximum range of about 1,000 miles, meaning they would never have been able to fly it to Egypt without refuelling. Given that they stole it, it's unlikely they would have been able to call in an offscreen refuel during the flight.
Factual error: Past the escalator, Steve and Diana walk past some literal punks who are wearing T-shirts. Some are appropriate for the period (such as the Bad Brains one, their debut album is from 1982) but the one with the cheetah leggings is sporting a Cro-Mags T-shirt; their debut album "The Age of Quarrel" (and its artwork is on the T-shirt itself) was a September 1986 release and this unfortunately isn't Wonder Woman 1986. (00:57:50)