When April contacts the Turtles in their lair, Leonardo is sitting on a couch with Donatello to his right and Raphael to his left. In the next scene, when Leonardo answers the Turtle Comm, Raphael is to his right, and the scene after that, Raphael is back on the left.
If the Turtles are impacted by Muckman and Joe Eyeball's mutagen due to their mutated DNA, why aren't Splinter, Bebop, and Rocksteady? All of them were mutated by the same ooze.