But he truly made his mark in 2014 when he released what was the year's most controversial documentary "The Truth Shall Not Sink with Sewol" (2014), drawing criticisms from the government when it premiered at the 19th Busan International Film Festival and kicked off a massive debate about censorship in Korea. The film is a journalistic account of the Sewol ferry disaster – using audio recordings, news clips and interviews – to convincingly assert that the government were grossly negligent in their recovery efforts, which claimed the lives of over 300 people earlier that year. It won Grand Prize at the Fukuoka Asian Film Festival in 2015.