Leung said Wong put in a lot of effort to find an accomplice of Cheung, who was sentenced to jail for 14 years, for research.
With the details from real life, Wong made the story dramatic yet convincing, Leung explained.
"A lot of audience members and critics give negative reviews to most of Wong's films, but Wong is still one of the highest-grossing directors in Hong Kong. Wong knows how to cater to audiences and earn money for investors, so I really admire him," Leung added.
The film's star-studded cast also includes Louis Koo Tin-lok and Gordon Lam Ka-tung.
