The examples they chose were the same examples that they received criticism over. If by "contrived" you mean they were practice exercises, well, of course they were. But are you seriously trying to claim that they also have to go through examples of every other situation a cop could get put in before someone could appreciate the gravity of those decisions? Might as well tell everyone they have to become a cop then. But it seemed like from this gentleman's standpoint, he didn't feel it was contrived at all, and HE was the one who initially was complaining.

"Part of doing the job right, i.e. working with citizens to get rid of crime, involves the police officers taking some risk."

Why? The whole reason you train is so that you don't have to take the time to stop and analyze the situation when there is no time to do such. It's one thing to play armchair quarterback, and something entirely different to BE the quarterback faced with a blitzing 250-lb linebacker. That was the whole point of this exercise: to demonstrate that in these situations there is no time to think. You don't have hours or days afterward to think about what you should have done, all you can do is act in that split second.

It's the same reason the recommended following distance in a car is 10 ft for every 10 mph - your brain has to have time to recognize and process the situation and then act. If there is already a pattern of action, that process takes only a split second. If not, the brain has to develop an action plan to follow. And we all know that when the adrenaline hits your system, the thinking part of your brain shuts down and the survival instinct takes over. The reality is that there is no way anyone can plan for every conceivable situation or outcome. That was the point of this exercise: to demonstrate just how difficult it is to think and act in a high-pressure situation.