After Zack the Black Ranger appears nearby some trees, while he is holding his Power Axe like a cannon, he mysteriously has bloody and bandaged hands. His hands were not injured at all before this time and will not be bloody after his fight with Goatan.
When Bulk and Skull jumped in the lake, the water washed away the mud on them, but at the end when the police brought them to the Youth Center, they're more muddy then before with no explanation.
When Bulk trips in the tire race, you can see the blue padding that he falls onto, although it is removed in the closeup after he falls.