Evolution! That Mystery and Wonder!! - S8-E50
Other mistake: When Dr. Gordon says that the candy was created to improve a Pokémon's health, Caterpie mistakenly has seven segments instead of six. Also, Ash, Brock, and Pikachu go from being in front of a bookshelf to not being in front of one. Additionally, Max and Ash's bags go from being absent to being present. (00:08:17)
Evolution! That Mystery and Wonder!! - S8-E50
Other mistake: When Caterpie and the city are first seen, part of Caterpie's body is mistakenly coloured yellow instead of green. (00:09:26)
Evolution! That Mystery and Wonder!! - S8-E50
Other mistake: In the shot before the Pokémon Trainer's Choice, Caterpie's mouth is mistakenly coloured yellow instead of green. Also, its shadow appears in midair. (00:09:45)
Other mistake: When Juan says, "I won my five ribbons and entered the Grand Festival," his reflection in his tea is not reversed. (00:08:05)
Evolution! That Mystery and Wonder!! - S8-E50
Other mistake: When Ash and friends are first in the laboratory, Pikachu's right cheek pouch is missing. (00:03:13)
Evolution! That Mystery and Wonder!! - S8-E50
Other mistake: When Max asks if Zander studies with Dr. Gordon, Pikachu's right cheek pouch is missing. (00:03:50)
Answer: Yes it ran away because Layla hurt its feelings.