no one was around to exactly witness the scene and seeing the brat cry near a tree with a broken hand... the lie was believable especially when it is coming from a goody shoes boy...
Arthur was still reeling from the shock. His voice barely a whisper, he stammered, "He... he was claiming the tree as his, Mrs. Hawthorne. I told him not to, but he wouldn't listen, and then he slipped and fell."