When Ray arrives in San Bernadino and is first being served at Macdonald's he is standing at the right side of the serving counter when the film pans back he is now standing and walking away from the left hand side of the counter.
When Ray is ordering food at about 12 minutes into the movie, he is shown switching order windows as the camera angles switch.
When Joan was introducing the powdered milkshakes, her husband seemed to disappear and reappear in the series of shots.
When the mother and her three children sit down next to Ray Kroc on the bench, the mother takes a bite out of her hamburger. In the next shot, the mother's hamburger is intact, still circular, no bite taken. The hamburger appears intact because she is only taking nibbling bites out of the bottom of the hamburger. The top of the burger remains intact because she only eats from the bottom, out of camera view.
When Ray Kroc first stands in line at McDonald's during his first trip he speaks to a beautiful black woman who tells him it doesn't take long.In the very next cut she disappears.
The doctor asked Mac McDonald if he was checking his blood sugar. There was no home blood glucose monitoring in the 50's or 60's.
In the movie, it's implied that the first Michigan McDonald's was in Grand Rapids; it is further shown on a map that there's a pin on the Grand Rapids location and nowhere else in the state. Actually, the first store in Michigan was on N. Larch Street in Lansing, Michigan--not in Grand Rapids. The franchise was owned by the first manager of the original Des Plaines restaurant, Ed MacLuckie. The Lansing location opened in 1957, followed soon after by a location in East Lansing, just off the campus of Michigan State University. The East Lansing location was a huge success, having at one point the larges sales in the nation because of its prime location near a college campus.
In clause 10 of the contract that Ray reviews and signs, the word 'supersedes' is misspelled as 'superceedes'.
When Kroc goes home for the first time from California, he cracks open a bottle of beer with a bottle opener. However, the bottle clearly had threads at the top indicating it's a twist-off bottle. Twist offs were not on the market in the mid-50's. They started entering the market in the late '60's.
While Ray Kroc is sitting down outside the original McDonald's a family sits down next to him. The straw in the woman's drink can be seen clearly that it is plastic. Plastic straws did not come out until the 60's.
When Ray is looking to drive out to California in 1954 he looks at a map and follows road. It shows "Temecula." Temecula wasn't a town until the 1980's.
When the employee gives Ray Kroc his first McDonald's meal , the straw is already unwrapped and put into the cup. For sanitary and hygienic reasons, the straw should have been given to him unwrapped to prevent employee(s) from touching it with their hands or lips. All straws from fast-food restaurants are to be wrapped up when given to the customer. It also should be noted that this is the 1950s, and sanitary laws regarding things like wrapped straws may not have been in place. It might have been seen as a convenience to have the straw ready for the customer back then before all of this.
The "Piggie Park BBQ" that Ray unsuccessfully tries to sell a mixer to is extremely weathered, with paint peeling off the underside of the drive-in awning and rusted metal visible in numerous places. The sign proudly announces that the restaurant had been open "Since 1950", which would only have been 4 years prior to the events of the film, an awfully short amount of time for the establishment to become as run down as it is seen.
When Mac and Dick are on the tennis court choreographing the kitchen layout, Mac bends over to draw with chalk. You can see the outline of modern mid-thigh boxer briefs through his pants. This type of undergarment did not exit in the 1950's.
Regarding McDonald's #1 in Des Plaines, IL. McDonald's announced that the building would be torn down as early as the end of 2017 due to repeated flooding of the site, the completed demolition ended in mid 2018. McDonald's has decided to donate the land to the city for grassy park area.
The film implies that McDonald's was the first fast food restaurant in the United states, which was founded in 1940. It is generally accepted that White Castle was the first ever fast food restaurant, which was founded in 1921.
When Ray goes to the movies, the marquee shows "On The Waterfront". The Now Showing case indicates that "Magnificent Obsession" is the current movie. Perhaps that title was a little too on-the-nose.
When Ray first called Dick to verify the number of multi-mixers to ship, dick requested eight multi-mixers. During Ray's restaurant tour, there are already several multi-mixers in the restaurant.
When Ray is looking at the map, he follows his finger along highway 66 and lands on San Bernardino. It shows some surrounding cities, one of which is "Moreno Valley". Moreno Valley didn't become an incorporated city until 1984. In the 1950's that city would have been called "Sunnymead" on a map.
Although set in the early 1950s, many of the buildings film flying flags are flying the modern 50 star version of today, which would not have come into existence until 1960 following the admission of Alaska and Hawaii as the 49th and 50th states.
When Ray Kroc is looking at the map to plot his route to San Bernardino to visit the first McDonalds, the city of Irvine, CA is shown on the map. This is an error due to the fact that Irvine was not incorporated as a city until 1971, and the Irvine Company did not start developing in that area until the 1960s.
When Ray Kroc gets his first meal at McDonalds, the cup has the words "coast to coast" in a navy blue and white band along the bottom of his drink cup. The sack has the same strip under the logo but the "coast to coast" part has been omitted. If this is only one of four McDonalds, the "coast to coast" part would not exist yet.
In the parking lot scene in Waukeegan in 1954, modern-day halogen/sodium lights are seen lighting the lot. Halogens were not introduced until the late 1990s.
San Bernardino is not that green and lush as depicted in the surrounding scenery. Southern California has a dry climate.
For the franchise in Schaumburg Illinois, the multi story background building is incorrect for that time period. At the beginning of this scene it shows a four story building in the background which is not consistent for the type and tallness of buildings in Schaumburg, IL for the later 1950's.
As Ray drives west through AZ, the sun's shadow is short to his driver's side, which would make it impossibly from the north. Even if he was driving north or south as driving west, the shadow would be longer.