The Prestige is the definitive deus ex machina cop out movie.
Ok, bad news, you have no idea of what deus ex machina is or you have not understood the movie.
*** I am assuming you are saying this because of tesla's machine and not the bale character being twins (we are constantly told how he behaves different by women in the story--this is suggested throughout the whole movie)
You took the very simple definition and applied it here
"Deus ex machina is a calque from Greek meaning "god from the machine".The term has evolved to mean a plot device whereby a seemingly unsolvable problem is suddenly and abruptly resolved by the contrived and unexpected intervention of some new event, character, ability or object. "
https://en.wikipedia.org/wiki/Deus_ex_machina
But this is not enough to truly grasp the idea. Was warp speed the deus ex machina of Star Wars?
now read further down the wiki page to truly understand DEM
"Aristotle was the first to use deus ex machina as a term to
describe the technique as a device to resolve the plot of tragedies. It is generally deemed undesirable in writing and often implies a lack of creativity on the part of the author.
The reasons for this are that it does not pay due regard to the story's internal logic (although it is sometimes deliberately used to do this) and is
often so unlikely that it challenges suspension of disbelief, allowing the author to conclude the story with an unlikely, though perhaps more palatable, ending."
ok, so here goes
Jackman tries to figure out how Bale is doing his trick. That is the overall question of the movie.
Jackman finds Tesla and somehow Tesla has a cloning machine.
Tesla having a cloning machine is not DEM.
This is not a cheat answer to main problem presented by the movie.
It is an answer that IN THE REAL WORLD IS UNLIKELY FROM WHAT WE CURRENTLY KNOW just like Warp Speed.
But it is not the crazy answer that resolves the central problem of the movie.
Tesla's machine actually solves ZERO problems. Jackman goes on thinking this is how Bale did his trick.
And ultimately ends up losing because he does not know.
Again, lets go back to Aristotle "a device to resolve the plot of tragedies"
- Ask yourself, did Tesla's machine resolve the plot of the tragedy? Or did the fact that Bale have a twin the hole time actually resolve the plot???
Now compare that to your poor understanding of DEM being "a seemingly unsolvable problem"-- you could literally have 20 DEMs in a movie if this is how you define it, which is fucking ridiculous. Fucking LOTR would be a landfill of DEMs.
Not to pick on you, but shit like this is really endemic of people now. They hear these words and maybe they wiki them, but they do not truly understand them.
So sick of hearing strawman and etc when they really do not apply at all, but they read a sentence about a complex idea and think they understand it.