Finally watched the fifth episode yesterday. The last episode felt different than the rest of the series, but it's hard to put my finger on why. They added some historic moral balance to Jared Harris' character; whereas Stellan Skarsgard's character came out looking better. The power plant managers looked even more cartoonishly evil and incompetent. I really like their decision to wait until the trial episode to explain the events leading up to the accident. The series wouldn't have worked remotely as well if they kept everything in chronological order.
I was also a fan of them using red and blue cards to describe what was going on in the reactor. Total gross oversimplification, but it worked well. I'm curious if it was well understood by the general audience.
Was Harris' monologue about lies in the original trial? That felt tacked on add emphasis to theme of the series? I also wonder if he really did explicitly site the frugality and stupidity endemic in the USSR. It was well known, but no one was dumb enough to rant about it on the record. ...then again, as the KGB agent implied at the end: if you know that you are going to die of cancer soon, might as well speak the truth and go for the quicker and painless route.