I just thought of something - if the mafia know what the hint is going to be in advance, it's possible that the options were.
1. Pointed ears.
2. Round ears (or something).
3. Color red.
Obviously I haven't looked into the specifics, but the person who chose the kill could be the group that had the least amount of mafia in it.
Say for example, there's 1 mafia who's in pointed ears (out of 6) and 2 mafia in round ears (out of 4) and 1 person who's red (out of 2) then obviously the mathematical best kill would be the 1 mafia in pointed ears.
Something along those lines could mean something? Like maybe it's best to lynch outside of pointed ears like Daniel was saying, due to the fact that the hint chosen should be the one MOST beneficial to mafia.
I'm not sure how much it matters but the mafia knowing the hint makes the hint so much less useful.