While April is going through the jungle in the beginning, she sticks her sword between her backpack and her back. However, the sword keeps disappearing and reappearing, and/or keeps changing sides.
When Michelangelo enters the Turtle's lair, he throws his skateboard to the ground near the front entrance before descending down a stairway. When he goes to sit on the couch, his skateboard reappears laying on the floor by the platform but earlier shots have clearly shown it was not there before.
When April puts her sword up after she cuts through some plants, the sword handle is next to her left shoulder. When the camera angle changes, the handle is next to her right shoulder.
After Raphael argues with Donatello, and Splinter is introduced, Raphael's bandanna briefly turns grey as he leaves.