The 2019 Anti‐Extradition Bill Movement in Hong Kong made international headlines as a leaderless movement. This leaderless feature may be an aftereffect of the 2014 Umbrella Movement, following which university students voted to disaffiliate with the movement’s leadership, the Hong Kong Federation of Students (HKFS). We conducted a study to examine the psychological factors that contributed to this disaffiliation, including the lack of perceived integrity‐based and competence‐based trustworthiness regarding the HKFS. We tested their indirect effects on the relationship between group identification with the movement protesters and the corresponding decision to disaffiliate with the leaders. This study recruited voters at a university in Hong Kong (N = 113) shortly after a referendum on whether to end ties with the HKFS. The results of an ordinal logistic regression suggest that lower perceived integrity‐based and competence‐based trustworthiness both significantly predicted the voting decision to disaffiliate with the leaders. Indirect effect analysis with bootstrapping found a significant indirect effect of voters’ group identification with Umbrella Movement protesters on the voting decision through perceived integrity, but not perceived competence.