Child Abuse?

Carter is a rough, tough kid. He always has some kind of goose-egg on his head from a crash, fall, etc... Last Saturday my mother-in-law took the kids hiking down at red cliffs and they had a great time. They came home with red sand everywhere! Carter had a little fall and when ever anyone asks him what happened to his head he says, "I fell down on a big rock." Last Thursday I was reading with my kids at school and my Aunt Grace (who works at the school)came walking by. Carter and I usually pass her in the hall when we are there and he never says a word to her even though she talks to him. Last week she came walking up and he said "mom look, there is your aunt Grace!" I said yeah and was amazed that he was going to notice her. She started talking to him and then said, "Carter, what happened to your head, did your mom hit you with a big stick?" and Carter said, "no, her hand." ..........He tells eveyone that he fell on a big rock, but because of the way she asked, he accused me of child abuse. We all laughed, I kept saying, "I wasn't even there when he got hurt, I promise."