When Kumail is eating fast food and receives a text saying that he is supposed to be on stage in 20 minutes, the text is marked as being sent 1 day before hand.
Although the film is set in Chicago and Emily is said to be at "City Hospital," a sign for Katz Women's Hospital at the Long Island Jewish Medical Center in New York is clearly visible when Kumail arrives.
In the opening scene at the Comedy Club we see Mary do part of her set. When she comes backstage where the men are, she is wearing a different outfit and her hairstyle has changed.
Although he lives in Chicago, Kumail's car has a New York inspection sticker on the windshield.
Kumail tells Emily that 'The Abominable Dr. Phibes' was made in 1969 by MGM. The film was released by American International in 1971.
When Kumail is leaving Chicago to go to New York City, all the cars have New York state license plates. They should have been Illinois.
Early in the film we see Kumail throw a photograph on the pile of pictures in his cigar box. Below several other pictures is a photograph of a woman in a light blue hijab. Later in the film he again throws a photograph on the pile. It is the same picture of the woman in the light blue hijab.
On the marketing image that shows all the characters, movie title etc, it shows Kumail's mother wearing a hospital visitors pass. She never went to the hospital.
When Kumail doesn't show up to dinner, his brother Naveed claims to have called him multiple times. Later on, Kumail checks his phone to see several missed calls from his mother and none from Naveed.
Movie is supposed to be an autobiography loosely based on their lives. They got married in 2007, there is a scene in which Kumail uses Emily's fingerprint to unlock her phone, but that technology was not present on the iPhones then.
In the hospital waiting room scene when Kumail first comes back after being told he could go home, Emily's mom's necklace is tangled in her glasses chain. In the next shot, they are separated.
When Kumail is outside the hospital room, his visitor badge on his black T-shirt is half covered by his flannel shirt then not there then half covered as the camera cuts back and forth to him.
The scene where Emily says she wants to go to a coffee shop has a digital clock where the time moves back and forth.
Near the end of the movie when Kumail is looking through the window in the hospital room door he can see Emily's head but when the shot switches to the other side of the bed it is obvious you would not be able to see her from the window because of the angle of the bathroom wall.
When Holly Hunter is signing papers to discharge her daughter from the hospital, she checks the time on her watch by looking at the bottom of her wrist. However, the face of the watch is on the top of her wrist, so she wouldn't be able to see the time.