A recent article in this space profiling the actress Xu Qinfang mentioned that Chinese sources refer to her being a real-life heroine for actions she took during the May, 1925 student demonstrations in Shanghai. As I wrote at that time, I would update that article when I found more information. It turns out that Xu did save the day for a film crew and for her studio's first filming effort, although her action was not so much heroic as quick-witted.
For background, I refer readers to the Wikipedia article on the incident. One hour after the massacre, director and Youlian studio founder Chen Kengran and a cameraman rushed to British police headquarters to film what they could. Arriving on the scene, they found policemen washing blood from the ground in front of the building. The police were taken by surprise, and when they noticed the filming approached the crew intending to confiscate their film. Thinking fast, Xu grabbed the camera and hid it on her person, correct in believing they would not search a woman. The camera was undiscovered, and in the coming days the Youlian crew added to it footage of the wounded in hospitals, operating room scenes, destruction in the surrounding area, campuses shut down by Chinese authorities to appease the British and British troops debarking at the Shanghai dock to reinforce the concession police. The film was edited into a three-reel documentary entitled "Wu Sa Hu Chao" 五卅沪潮 (The May 30th Movement in Shanghai). The film could not be shown in the foreign concessions, but was screened in a number of small Shanghai theaters outside and in Suzhou.
The protests continued, and spread to Canton (today's Guangzhou) and Hong Kong, where it ignited a general strike having far-reaching implications for the film industry there, shutting it down for several years until it was almost single-handedly resurrected by Li Beihai.
For further reading:
Fang, Fang (方方). Zhongguo Jilupian fazhan shi 中囯纪录片发屒史 (History of the Documentary in China). Beijing: China Theatrical Press, 2003, pp.40-43.