The scene where young Jamal tries to steal food, hanging upside down on the train shows a window which had removable bars (it's like a fire escape). These kind of bars were not installed until after the 2002 Gujarat riots.
The trains on which Jamal and Salim escape and live for many days have compartments painted in blue color. The blue color compartments came into existence at a later date. The compartments were painted Red back then.
At the end of the last song and dance sequence on the railway platform, hoardings for shows on NDTV Imagine (and entertainment TV channel) are prominent. NDTV Imagine launched in 2008 and the promotion could not have began in 2006 - the year where the story of the film happens in.
In the scene where Javed is partying with his friends and Latika is held captive, the audio playing in the background is from the movie Don (2006), whereas the visual shown on TV is from the movie Yuva.
One of the reporters talking about Jamal after his arrest asks "Will he be back to win another 20 million rupees?" This is incorrect however, as he had only won 10 million rupees and 20 million was the final prize. So she could have either meant "Will he be back to win another 10 million rupees?" or "Will he win 20 million rupees?"
When Jamal is at the front gate of Javed's house and is telling the guard that he is the new dishwasher, his shirt changes from a dark patterned long-sleeved button-up shirt to a lighter blue short-sleeved button-up shirt. When Jamal enters the house, he is wearing the long-sleeved shirt again.
A large pimple on the right side of Jamal's face appears then disappears then reappears, depending on whether he is being interrogated by the police or is answering questions as a television game-show contestant, even though those events supposedly occurred in the plot within a span of just a few hours.
When Javed says, "The cricket is on," and switches the TV channel away from "Who wants to be a millionaire?", it is obviously a rugby game that he switches over too, yet on the TV in the next room it is actually cricket.
When Jamal is asked by Latika to leave the mansion and forget about her, he accidentally pulls up one side of his collar when taking off his apron. However, in the next shot, his collar is down again. When he actually leaves the mansion his collar is up once again.
While preteen Jamal is at the opera wetting his face with water, his black eye, which he sustained as a tour guide for the American couple after Salim orchestrated the stripping of the car parts, briefly switches from his left eye to his right eye when he turns his head to the right (no, not in the reflection in the water) then returns back to his left eye.
The "Millionaire" format is sold worldwide with the same rules, with small variations, like the amount of the final prize to adjust for the currency value. One rule is the presence of the two milestone - or "parachute" - questions (#5 and #10), to prevent the contestants' prize from falling further if they answer wrong. Yet the host keeps mentioning that if Jamal answers wrong he will "lose everything" or "get nothing".
In the movie, the correct answer to the question of who wrote the song "Darshan Do Ghanshyam Naath" is shown as 16th century poet "Kavi Surdas". However in reality, this song is written by Gopal Singh Nepali for the movie Narsi Bhagat. This song is also credited as traditional and originally written by 15th century poet Narsinh Mehta, whose life that film is based on. (Many, including the film, mistakenly attribute it to the 16th-century poet Surdas due to the fact that Surdas was blind and the song is a prayer asking God to "appear" before him, for his "eyes thirst for Your sight".)
In one scene, when teenage Salim and Jamal are at the Taj Mahal, there is an external shot where a passing guard looks at the camera and says, "Stop filming. Stop filming." This was included purposely by director Danny Boyle for the sake of realism.
Both Jamal and Salim speak fluent English when they're teenagers. The movie was originally supposed to all be in English, yet the actors that played young Jamal and young Salim had some trouble with speaking English. Director Danny Boyle asked producers to have the beginning in Hindi, and colored the subtitles to make them more appealing. From the storyline, Jamal and Salim probably learned from tourists.
The original TV show "Who Wants to be a Millionaire" is recorded in studio some days before the actual broadcast. The show that we see in the film is broadcast live, which raises the incongruence that the person from home can easily see the question on TV, having plenty of time to come up with an answer before receiving the actual call. This explains the need to have the questions reread on the phone, and the credibility of the time limit. Moreover, the call itself is never directed to a mobile number, to prevent connection troubles, and for the same reason it's never issued directly when the contestant asks for it; the call is first made in the very moment the contestant begins his round and it's then kept live (but soundless) until the contestant calls for the hotline. As a side fact, after the hotline has been used the contact is still kept, so the contestant's people can hear live what happens from then on. However, this kind of show may have a 10-15-minute time delay.
The young Salim and Jamal are shown to attend a primary municipality school in Mumbai. These schools do not have The Three Musketeers in syllabus. However, this could have been a school that was built in the slums by an external organization such as a charity.
While driving the car after escaping from Javed and going towards meeting Jamal, the scar appears on right side of Latika's face although it is on left side of her face before the scene when Salim slips her hair and in rest of the movie. However, Latika's face is seen in the rear view mirror of the car; therefore, the scar on her left cheek appears to be on the right cheek.
Jamal is uneducated and yet he can read and write. We see this in his job at the telemarketing firm. He also mentions that he can read while on the Millionaire Show. However, it isn't unreasonable to assume that they attended school and learned to read and write before their mother was killed. Indeed, Jamal says that he can read when asked about "The Three Musketeers".
Indian culture has absorbed many western terms, and seeing as "Who wants to be a Millionaire" is a western show, with a copyrighted and world famous title, they'd either have to break from the other versions to maintain cultural accuracy, or maintain notoriety and keep the title. Plus if you turn on the subtitles on the DVD you can read that the host mentions "crore" several times at the end, which would make sense in their predominantly bilingual culture.
Jack Hobbs (the question about cricketers scoring first class centuries) is partly correct with the answer of 197. Jack Hobbs has stated that although 199 were done in a technical sense, as 2 of these were in exhibition matches they should not count and as such have never been officially recognized by Wisden Cricketers' Almanack. A quote from Jack, 'Don't include those,' he told the late John Arlott. 'They were exhibition matches. Vizzy wanted to list our hundreds on the walls of his pavilion. We knew we'd got to score hundreds - so did the bowling side. They were not first-class in any sense.'
At the end of movie where Latika is shown on the platform of the CST terminus/ station in Mumbai, she is briefly shown in full sunlight - the station is fully covered with a roof with only very limited chance of sunlight through small openings and colored windows.
At the very end of the movie, after he wins the show and become famous on TV, Jamal waits for Latika in a train station. Yet none of the passers-by notices that he is the winner of the show and consequently a millionaire.
In the final question, the apostrophe is shown as after the s in Dumas'. However, when it shows Javed on the phone, the television in the background shows the question, and Dumas' is spelled as Dumas's.
After revealing the answer to the question of which cricketer has scored to most first class centuries, the host reveals that Jack Hobbs scored 197 centuries. In fact, he famously fell one short of the 200 milestone by scoring 199 centuries. However, both figures can be accepted as correct. The Association of Cricket Statisticians and History, in 2006, revised the status of many 19th Century and pre-War matches, which produced new statistics, giving Hobbs 199 first-class centuries. However, Wisden, often seen as the "cricketing bible", declined to recognise the new figures and still records Hobbs as scoring 197.