This story seems sensationalized to me. It's not like the trainee is some Joe Blow off the street. You don't set in the cockpit of an A330 without having considerable flying experience to begin with. Besides there was another pilot in there with him.
I also have to wonder how much help the captain would be if he was exhausted and sleep deprived (speculation on my part).
There is something wrong here but my guess is it has more to do with the way airlines treat their pilots rather than the actions of this one particular captain.