Question: What Cantonese slang term for Westerners is referenced by the title of a 2006 film by Nick Broomfield?

Context articles: Ghosts (2006 film)
Heidi Fleiss: Hollywood Madam
His Big White Self
Aileen Wuornos: The Selling of a Serial Killer
Gweilo
The Leader, His Driver and the Driver's Wife
Cantonese slang
Battle for Haditha
Beard (companion)
Diamond Skulls

Ghosts is a 2006 drama film directed by Nick Broomfield, based on the 2004 Morecambe Bay cockling disaster.
 The title is a reference to the Cantonese slang term "Gweilo" (鬼佬), meaning "ghost man", used for white people.
Heidi Fleiss: Hollywood Madam (1996) is a feature-length documentary film by Nick Broomfield.
 It is an examination of the woman herself, Broomfield attempting to uncover if she truly is a 'horrible person', and what made her that way.
His Big White Self is a 2006 documentary film made by Nick Broomfield.
 It is a follow-up to his 1991 film "The Leader, His Driver and the Driver's Wife".
 It was shown for the first time as part of More4's Nick Broomfield week which started on 27 February 2006.
 The documentary follows Broomfield as he returns to South Africa 12 years after the collapse of the apartheid regime.
 His previous film focused largely on JP Meyer, a driver for Eugène Terre'Blanche (the leader of the far-right Afrikaner Weerstandsbeweging), and JP's wife, Anita.
Aileen Wuornos: The Selling of a Serial Killer (1993) is a documentary film about Aileen Wuornos, made by Nick Broomfield.
 It documents Broomfield's attempts to interview Wuornos, which involves a long process of mediation through her adopted mother Arlene Pralle and lawyer, Steve Glazer.
Gweilo or gwailou (, pronounced ] ) is a common Cantonese slang term for Westerners.
 In its unmodified form, it applies only to European ethnicities and has a history of racially deprecatory use.
 Cantonese speakers frequently use "gwailou" to refer to Westerners in general use, in a non-derogatory context, although whether this type of usage is offensive is disputed by both Cantonese and Westerners alike.
The Leader, His Driver and the Driver's Wife is a 1991 British feature-length documentary film set during the final days of the apartheid regime in South Africa, particularly centring on Eugène Terre'Blanche, founder and leader of the far-right Afrikaner Weerstandsbeweging.
 The film was directed by Nick Broomfield and released in 1991.
 It received an average of 2.3 million viewers during its screening on Channel 4.
 A year later it was the subject of legal action brought by the journalist, Jani Allan, in what has been described as "the libel case of the summer".
 In 2006, Broomfield released a follow-up, "His Big White Self".
Cantonese slang is a type of slang used in areas where Cantonese language is spoken.
Battle for Haditha is a 2007 drama film directed by British director Nick Broomfield based on the Haditha killings.
 Dramatising real events using a documentary style, "Battle for Haditha" is Broomfield's follow up to "Ghosts."
 The film was aired on Channel 4 in the UK on 17 March 2008.
Beard is a slang term describing a person who is used, knowingly or unknowingly, as a date, romantic partner (boyfriend or girlfriend), or spouse either to conceal infidelity or to conceal one's sexual orientation.
 The American slang term originally referred to anyone who acted on behalf of another, in any transaction, to conceal a person's true identity.
 The term can be used in heterosexual and homosexual contexts, but is especially used within LGBT culture.
 References to beards are seen in mainstream television and films, and other entertainment.
Diamond Skulls (also known as Dark Obsession) is a British 1989 thriller directed by Nick Broomfield who also co-wrote with Tim Rose-Price.
 An established documentary filmmaker, this is Broomfield's first work of fiction.It is produced by Tim Bevan and Jane Fraser and stars Amanda Donohoe, Gabriel Byrne and Struan Rodger and has a music score by Hans Zimmer.
It includes the last film performance of Ian Carmichael.