Granted I have not played the last few games with you schmucks, but the GF that I have seen was always immune to night kills, a vig, PGO, and the sort could not kill him, he had to be lynched.
Also, I am not sold on the flavor indicating an attack for all of the stuff just mentioned. While snake is poisonous, it attacks like a constrictor, not with its venom in the story. If you wanted to stick with poison, it is possible there is a poisoner in play (I can think of a couple occasions in the story that would make sense) but its possible it forgoes the mafia kill and only has a percentage chance to work. If that was the case though there would likely be a poison doctor in play to indicate that.
To me, it just seems that the flavor, for all the reasons mentioned above, indicates an escape not necessarily an attack.
I hit Brett right in the feels.