When you're mafia and you have successfully blitzed, do not gloat that you have won the game. Continue acting as if you are lynching correctly. Mafia also has this tendency to all kick to force the 15 second timer. When you do this, you're drastically increasing the chances that a town vegs or GRS even though you've already won. One kick to lock the votes is sufficient. Push for the lynch without admitting you're mafia and guarantee that all town will vote believing they have a chance to win.