When Wile is tossing the boomerang up and down his tail disappears for a few frames.
When Coyote has set up a giant boulder to drop on Roadrunner, he has a plumb line and plumb bob attached to show him exactly where the boulder will fall when he drops the boulder. He then goes to his blueprints to double check his plans. He then goes to watch for Roadrunner, spots him, then gets ready to pull a cord which will drop the boulder. But when this image is shown, the plumb line and plumb bob are no longer attached to the boulder, even though he never actually removed them, or even had time to remove them.
Wile E. Coyote's eyes turn white just before he chases Roadrunner.