Flashbang is bugged currently and whenever the Killer is performing a Mori, Flashbang blinds will crash the game of the Killer, force them to DC, and give them a DC Penalty for crashing. This applies to Firecrackers as well.

Part of this has to do with Flashbang messing up the camera positioning since the game is unable to properly register the blind effect and does not know what to do.

This even works against Tombstone Myers as well.

Keep in mind that it does require good timing to pull this off, but it is easily abusable by experienced players and can ruin games; this should be killswitched, along with firecrackers.