The cast, co-director Loveleen Tandan, music director A.R. Rahman and the Vikas Swarup's novel 'Q and A' on which the film is based are all Indian, as is the location, Mumbai's sprawling Dharavi shantytown.
That - and a part-Hindi dialogue - is good enough, they proudly point out.
'The movie is totally Indian,' Indu Mirani, entertainment editor at the Mumbai Mirror newspaper, told AFP. 'It's really good to know that a film that's so totally Indian can appeal to so many people internationally.'
The British angle was also irrelevant, she added, rejecting suggestions that Bollywood directors may be piqued at an outsider making an internationally successful movie about India, in India.
'Twenty years ago when Richard Attenborough made 'Gandhi', even then there was an attitude of, 'why does it take a foreigner to promote India?' Why does it matter who does it so long as a good film is made?,' said Ms Mirani.
Industry analyst Taran Adarsh agreed, saying Indians were 'euphoric' at the Golden Globes win and the potential for Oscars success.
'It may not have been made by an Indian but it puts India on the world map,' he told AFP.
'The fact that it has been acknowledged on a global platform, that says it all... It's a favourite for the Oscars and I'm keeping my fingers crossed.'
Bollywood, known for its Hindi-language song and dance movies, has been branching out in recent years to tackle contemporary issues, from Islamist extremism to the lives of workers in the booming call centre sector.
With the success of 'Slumdog' - and its depiction of the harsh realities of life in Dharavi - both Mr Adarsh and Ms Mirani believe more directors will move away from escapist, feel-good movies towards portraying everyday themes.
'In 2008, we had various different films being attempted. They worked at the box office and it shows that people are looking at alternative entertainment,' said Mr Adarsh. 'The audiences are there for these films.' Ms Mirani said she could see 'Slumdog' leading to greater overseas interest in Bollywood.
Some, though, still disagree that the movie's subject matter provides a bankable Bollywood formula.
Films like Sudhir Mishra's 'Dharavi' (1992) and Rabindra Dharmaraj's 'Chakra' (1981) have previously tackled working-class poverty and hardship but without box office success.
Big-name stars have also been reluctant to alienate their core middle- and upper-class audiences with gritty realism.
As such, veteran film producer and director Mahesh Bhatt believes Indian audiences still cannot bear too much reality.
'India lives in Dharavi. Our cinema is Disneyland. It is all about fantasy.
If I make a film like 'Slumdog Millionaire' I will not get any distributors and no-one will touch this film,' he said.
'Indian consumers don't need such subjects and it does not bother them.' Which opinion is right could be known on January 23 when 'Slumdog' has its Indian premiere.