Shoppers at a Walmart in Henderson, Oregon, froze when a six-year-old girl, mute and visibly terrified, sprinted across the store and clung desperately to a tattooed biker in a leather vest. To most, he looked like the last person a child would trust. But within minutes, it became clear the little girl had chosen exactly the right man. The biker, towering at 6’5” with a …