Sins of the Fathers Chapter 1: Doctor Strange - S3-E1
Continuity mistake: When Peter wakes up from Baron Mordo's illusion, he is wearing a monk's robe with sneakers and is barehanded. He removes the robe, revealing he was wearing his Spider-Man costume underneath, but his gloves and boots magically appear on his hands and feet as well. (00:09:45)
Sins of the Fathers Chapter 1: Doctor Strange - S3-E1
Continuity mistake: The hole in Dr. Strange's wall created by Baron Mordo's servants changes size and shape when Spider-Man is hanging Dr. Strange out the window. (00:10:25)
Sins of the Fathers Chapter 1: Doctor Strange - S3-E1
Continuity mistake: After Spider-Man, Mary Jane, Dr. Strange and Wong escape from Baron Mordo's lair, the lair itself disappears into thin air because of, according to Wong, the fluctuation of diminishing portal energy. When Spider-Man is saying farewell to Dr. Strange, the lair is there again. (00:18:30 - 00:19:05)
Sins of the Fathers Chapter 3: Attack of the Octobot - S3-E3
Continuity mistake: When Doc Ock is being taken away in handcuffs at the end of the episode, his mechanical arms are missing. The arms were fused to his spine, so the police couldn't have confiscated them.
Sins of the Fathers Chapter 3: Attack of the Octobot - S3-E3
Continuity mistake: When Doc Ock is about to unmask Spider-Man in his lab, there is a brief shot of Doc Ock standing under a night sky. This is from their rooftop battle in the previous scene/episode.
Sins of the Fathers Chapter 7: The Man Without Fear - S3-E7
Continuity mistake: When talking with his father and Smythe, Richard Fisk's grey pants briefly turn into the same color as his suit jacket.
Sins of the Fathers Chapter 11: Carnage - S3-E12
Continuity mistake: When Carnage escapes from prison a shot of venom escaping is used before changing back.