Factual error: Lord Rama is shown holding the bow in the right hand and raising the left hand for blessings. In Hindu practice the blessings are always given by right hand.
Continuity mistake: When Jamal's gang steals parts of the car, Jamal is hit by the driver and gets his left eye swollen. However, in the scene when he washes his eye, his reflection in the water shows that 'his' right eye is swollen, then in the next scene it is his left eye that is swollen.
Continuity mistake: Jamal follows his brother to Javed's house and sees Latika. Later he is forced to leave the house, and while standing at the door, the collar of his shirt is lifted. Then the shot switches to Latika and when it returns to Jamal, the collar is in place. The shot changes again and as he stands outside, the collar is lifted again.
Factual error: No version of "Who Wants to be a Millionaire", regardless of what country it is in, allows for a bathroom break after the question has been posed and before that question is actually answered by the contestant. The show is pre-recorded with scripted times for breaks. Jamal could never have been in the bathroom where the host gives him a fake answer to a question posed but not yet answered. This clause is in the contract of all contestants who appear on the show.
Factual error: When Jamal is lowered from the roof of the train, Salim is seen from below leaning way over the edge of the train. Because of the curvature of the roof, and the fact that he was supporting Jamal but the rope wasn't anchored to anything, there's no way Salim could have leaned over that far.
Continuity mistake: On the final question, it is displayed on TV as "Dumas'", but on the close-up of the on-stage monitor, it says "Dumas's".
Factual error: Mr. Vikas Swarup's book refers to "Ankhiya Hari Darshan Ki Pyasi" as the song by saint-poet Surdas. The song, Darshan Do Ghanshyam Nath Mori Ankhiya Pyasi, that features in the movie, is from 1957 film Narsi Bhagat which was directed by Devendra Goel. The film was based on the life of 15th Century Gujarati saint-poet Narsinh Mehta, who was a devotee of Lord Krishna. The song, based on one of the oldest ragas-Rag Kedar, was written by eminent Hindi poet and Bollywood song writer Gopal Singh Nepali and not Surdas as the movie claims.
Continuity mistake: In the song 'Jai Ho', at a certain point the time display in VT station shows 00.58.37, but in the next scene the time is 00.58.33.
Continuity mistake: When Jamal arrives on a train to VT station, he is travelling on the first track. When he alights from the same train, he is on the second platform.
Factual error: One of the questions Jamal has to answer is "Who invented the revolver?" to which the answer is given as Samuel Colt. Colt didn't invent the revolver, or even claim to invent it - he merely took a form which had existed for many years and substantially improved it. For example, Elisha H Collier patented a flintlock revolver in 1818 when Colt was only 4 years old which was produced in numbers for the British forces in India. More info: http://en.wikipedia.org/wiki/Elisha_Collier.
Continuity mistake: After Jamal used his 50/50 lifeline to eliminate 2 answers to the question "Which cricketer has scored the most first class centuries in history?", only answers B and D are left. Jamal flips between "A" and "D." He initially answers "A", which was Sachin Tendulkar. When pressed by the game show host he answers "A: Jack Hobbs." He then states "D final answer." "A" was not a choice after he used his lifeline, and would have been the incorrect answer.