Many scienist are rethinking their ideas that TRex's were hunters. Many now believe that the t-rex was a scavenger that searched for carrion.
Actually, that's the minority opinion.
The majority is holding to the belief that Rex was a hunter.
T-rex as a hunter makes no sense. If it's running at full speed to catch its prey, and it trips, it's dead. It has no means of breaking it's fall. The force of the impact would pretty well detonate the T-rex's skull.
The scientific comunity is pretty slow to accept new ideas. Archeologists are the worst, but the paleontologists don't seem to be too far behind.
But the fossil footprints show that, whether or not it makes sense, the T Rex DID run at full speed.
Hell, the full speed estimate is BASED ON THE FOOTPRINTS.
See, this is what I find wrong with Jack Horner's scavenger theory.
The TRex has hunter teeth, not scavenger teeth.
The TRex DID run at full speed, whether his logic says it could or not.
They've even found dinosaurs with healed TRex wounds on their bones, if I recall.