The mayor, who can vote and act as 3 votes (in the game setup I was playing in), lost in a 1v1 against the Mafia. SK killed the consig, and the GF killed the SK. GF was left and so was I. I used the -vote the previous day, and the option for my powers to last a few days was enabled. So, I could have lynched off the mafia myself and won. Instead, the screen showed up as "The Mafia has won" the day after the night the SK and consig died.
Solution proposed: Set up an event where if the Mayor and a Mafia role are left on the next day, allow the day to continue, so if the powers have been used before by the mayor, then he loses. If he still retains his powers, then he can still win. If you want to make the game like reality, then keep it how it is. But in my experience, too many people are bad and leave, so it's not like reality.
Problems most likely going to face if solution was accepted: From what I've seen, you set up an event in general terms. If one town and one mafia are left, town loses. If one town and one serial killer is left, town loses.
Suggestion to fix that problem: evaluate how your events are set up now. Make the game more reasonable, setting up complicated events for the last day. I've seen too much bullshit wins when I could have (and should have) won.
Thanks for reading. Hopefully that not only this specific problem is fixed, but all winning events are fixed and made more reasonable. If you didn't read my wall of text, please do so, as it will help and give the implication that I'm not another retard raging on the forums saying something didn't work out how I wanted it to.