With a high rate of descent in conjunction with a nose high pitch attitude,
Interesting and unusual. I am aware of a tail scrape on a B777 landing due to the Vref speed manually inputted incorrectly. (Why do some people insist on manually knocking off a bit of weight for the descent and approach and typing in a revised landing weight instead of selecting the present weight figure which at worst will give you a 2 knot greater speed?)
My experiences of someone's first landing on type after a long flight is a tendency to under flare and a firm arrival. I wonder if the trainee on this flight flared late and continued to raise the nose as the wheels touched, possibly aided by a Captain rapidly increasing back pressure. I'd be interested in what the nose pitch was when the tail scraped. For a normal landing the nose is raised to no higher than 5 degrees and the tail would not scrape until at least 8 degrees pitch or so. An extended flare can lead to a tail strike but that would not give a firm landing.