Continuity mistake: After surviving from drowning in the river, Cassandra has a blanket over her back. The blanket is covering her forearm or not, depending on the shot.
Continuity mistake: When Ben asks Cassandra to take her oxygen, his hair is messy. A shot later, it's nicely brushed.
Continuity mistake: When Cassandra is checking stuff inside a luggage, her ponytail is either falling over her chest or not, depending on the shot.
Continuity mistake: Ben tosses a fortune cookie at Cassandra, and aims at grabbing his oyster pail. An instant cut later from a different angle, the pail is already in his hands.
Continuity mistake: At the hospital, the nurse that holds the clip folder has both hands apart or together, depending on the shot.
Continuity mistake: At the hospital, Cassandra is talking to a nurse when a kid shows a drawing he made. Right then, an Afro-American man suddenly walks by out of nowhere.
Continuity mistake: At the hospital, Cassandra is cleaning the top of the soda can with the palm of her hand. An instant cut later, she is opening it.
Continuity mistake: When the skater girl stops in front of the ambulance, there's no car ten meters behind her. Half a second later, a car suddenly appears. There is no continuity with the cab behind either, which should be meters behind nor with a pillar that disappears.
Factual error: The ambulance drives by a Blockbuster with posters for the movie Big Fish. Madame Web is set in the Spring-Summer of 2003 (judging by the trees), but Big Fish premiered in December 2023 and the VHS came out in April 2024.
Continuity mistake: Constance's baby's right arm is uncovered except for the final shot where the shroud is suddenly covering him.
Continuity mistake: When Constance gives birth, a strand of hair on her forehead appears and disappears randomly between shots.
Revealing mistake: When Constance's baby is taken out of the water, she is an obvious doll who doesn't wink or move a single inch. She even cries, but her mouth doesn't move. In some shots, she is replaced by a real baby.
Continuity mistake: The position of the hands on Constance's baby keep changing all the time.
Continuity mistake: When Ezekiel takes the jar from Constance, his index finger is below the top. From the opposite angle, it stands out.
Continuity mistake: When Ezekiel points the gun at Constance, he holds the gun with one or two hands depending on the shot. This swaps back and forth.
Continuity mistake: Constance takes the umbrella away from Ezekiel by grabbing the shaft. An instant cut later, she is grabbing the handle.
Continuity mistake: When the movie begins, the way Ezekiel holds the umbrella handle (higher or lower) changes between shots.
Continuity mistake: After Constance tells Ezekiel that "spiders supercharge their cellular structure," the camera strap over her elbow moves upwards towards her neck. This changes back and forth all the time.
Continuity mistake: When the movie begins, Constance's hair is falling loose on her face when she is about to take the picture. When she stands up, it's fixed and only a loose strand of hair falls. This changes back and forth.
Audio problem: When the movie starts, Ezekiel says, "I agreed to provide security to you because I thought you were close to fighting the spider," but his mouth is closed.
