Case closed? T. Rex was a hunter not a scavenger

Peter Larson, a paleontologist at the Black Hills Institute of Geological Research in South Dakota says that a Tyrannosaurus Rex (T. Rex) tooth found inside the healed tailbone of a duckbill dinosaur indicates that T. Rex was a hunter not a scavenger. Here's the story from the National Geographic. Below is a clip from Walking with Dinosaurs (1999) a mother T. Rex making a kill for her children.