Trivia: During Borden's performance which ends with Angier shooting him, on at least two occasions the bill for the show can be seen off to one side. About halfway down is the name "Harry Dresden", the name of the wizard protagonist from the Dresden Files book series by Jim Butcher.
Trivia: The "Chinaman" in the movie was based on a real-life magician. He wasn't Asian at all, he just dressed and lived the part. The first English he ever spoke in his career were his last words. When a bullet catch went awry, he uttered the words, "My God, I've been shot" just before his death.
Trivia: There are a couple times in the movie, where if you listen carefully, you can hear Angier's English accent slip through (such as when he says to Olivia "He lives his act"). These are subtle clues to the later revelation that Angier is a British aristocrat pretending to be an American magician.
Answer: They were twins. Tesla didn't make a matching machine for Borden - all he made for the twins was a machine that made some light and noise to enhance their trick. The Borden brothers sent Angier off to see Tesla on what they thought would be a wild goose chase, just to get him out of the way for a while - they would never actually give away the real secret to their trick. They never anticipated that Tesla could actually have built the machine in question.
Tailkinker ★