Fake.
First, Corythysaurus would have blasted his ass with a sonic boom before he could even have really started. Seriously. BLASTED. HIS. ASS
Second, they loved about 10 million years apart. That may not seem like much to us fellow humans, but in dinosaur years, its scientifically notable.
Finally, while T. rex's English was quite good, it's vocabulary was limited. source
Don't be paranoid. Be like me. SCIENCE!