Revealing mistake: When he's attacked in Down Below, Dr. Franklin is shoved against a station bulkhead/wall that wobbles when he hits it. (00:15:30)
Sins of the Fathers Chapter 1: Doctor Strange - S3-E1
Revealing mistake: When Mary Jane and the other servants of Baron Mordo are flying through the city, they literally disappear into thin air. Probably a problem with rendering the 2D animation within the 3D animation. (00:01:00)
Revealing mistake: When Silver Surfer is flying between the buildings with the Statue of Liberty in the background, the building on the right briefly vanishes from the screen. (00:00:55)
Iron Man, on the Inside - S2-E6
Revealing mistake: When Julia is shaking pepper onto Hawkeye's nostrils, the edge of an animation cell is visible in Hawkeye's philtrum area. (00:16:48)