Fridge Brilliance: Christian Bale's performance becomes a lot more impressive when you realize that he's really playing two different people. It takes some close watching, but soon you can detect the subtle distinctions between the characters in the performance—a very impressive amount of work for something the audience is not supposed to notice. Another layer of fridge brilliance comes when you realize that there's another art form that involves the artist doing a lot of work the audience isn't supposed to notice—Magic.
It also makes the scene where Borden is talking to Fallon about Sarah even more heart-wrenching. On a first watch-through, you just think he's asking a friend to help him out with his marital troubles. On the second watch-through, you know it's one brother begging another to help him keep his beloved wife, especially when said brother is a large part of the reason why said wife is so unhappy.
When Borden said that he couldn't remember whether he used the new knot, was he lying, flustered, or not the right Borden?
Borden's journal entry regarding his thoughts on the incident had him saying that he "struggled with himself", two halves insisting that they tied two different knots. Which implied that it was a case of miscommunication between the twins. You can also see hints of this in performance itself, as the twin that causes the tragedy doesn't drop the knot while he ties it, unlike the twin in the first performance.
Several little details also become apparent when you know Borden and Fallon act as a form of bait and switch. Ever wonder how Borden suddenly appears in Sarah's apartment asking for tea?His brother broke in and waited for her to come home.Wonder why Borden only loves his mistress or family on specific days?Because it's not the same man each day.How come Fallon comforts Borden's daughter when he's fighting with the woman he normally loves?Because he's really her father, and it's her uncle arguing with her mother.
An additional example: One scene has Borden promising to take his daughter to the zoo after he runs some errands, but when he sees Fallon, he asks him to take her instead as he's busy. Whilst it seems cold hearted initially, it becomes apparent that, since a man who at least resembles Borden took her, he did still technically keep his promise.
Or possibly, At that moment, Fallon was her actual father and the current Borden thought it'd be best if he took her
Fridge Horror: In a fashion reminiscent of Quantum Suicide, each time Angier uses Tesla's device he appears to teleport across the room while a clone is dropped into a water tank to die. Equally possible though is that the 'original' Angier in each case is the one to drown, with a clone appearing elsewhere. But as far as the copy is concerned, he is the real Angier, and he has survived the trick. The end result is that not only does the 'template' Angier die every time he performs the trick, but that it comes as a surprise. Every. Single. Time.
Worse still, each time the trick is performed, the copy believes he has survived yet again. By the end of the film, that particular iteration of Angier believes he has survived the trick potentially dozens of times; what reason does he have to believe that this time will be any different? Except it is. It always is.
Whether the above is true or not, by the end of the film the original Angier has been dead (by his own hand, no less) for quite some time, either shot by his clone, or drowned in his box
Either that or there is no Angier/corpse that is more or less "original" and the entire debate is an exercise in arbitrary definitions.
Fridge Logic: If the only bar to pulling off the Transported Man with body doubles is finding a good enough doppelganger, Angier only really needed to clone himself once, keep the clone alive and carry on as a Bordenesque double-act. On the other hand, he'd then have the Cloning Blues to deal with.
It's halfway between Logic and Brilliance. Yes, he absolutely could have. However, by that point he's got tunnel vision something fierce: remember, back when he correctly guessed the trick was done using a body double, Borden mocked him mercilessly for it. Thus, in his mind the "correct" way to do the Transported Man doesn't involve that particular schtick. And so he flies right past the obvious solution to set up his own, needlessly complex and cruel version.
The audience is already presented with the reason why two live Angiers wouldn't work: Angier's double earlier in the movie stealing the applause and blackmailing him. The Angier in the box would always be jealous of the the Angier who was the Prestige. Killing the Angier in the box is the best way Angier knows how to deal with the problem.
It also shows a key difference between Angier and Borden. Borden is willing to sacrifice his own life for magic; Angier will sacrifice others.
When you put it that way, it's much easier to see who the black is in this Black and Gray Morality.
Although, it's also revealing of Angier's motivation as a performer: He would rather die than be the one in the box
Actually, his motivation is the audience, receiving the applause.
