There are two known cases of HKPF using flashbang grenades. Once at PolyU on November 17th, and then 20 meters from the crush during the Yau Ma Tei Stampede on November 18th. The one used in Yau Ma Tei was a 9 Flash-Bang, whereas the one used at PolyU was a single flash. Immediately after the previous clip ends, footage of the big crush in the YMT Exit A1 alley…