A Traitor is considered Normal on mafiascum.net, as long as it:
is Mafia-aligned
identity is not known by the Mafia team, although they should know a Traitor exists
cannot be recruited to join the rest of the Mafia team, and (unless Bulletproof) is killed if shot
is endgamed if all other Mafia are dead
gives a "guilty" result to Cops, an "innocent" result to Gunsmiths, and a "Traitor" result to Role Cops
If you want a Traitor that cannot be killed by its team, make it a Bulletproof Traitor. (A Traitor that investigates as though they were town is not Normal, because the Godfather role is not Normal.) Roles like this should return full names (e.g. Bulletproof Traitor) to a Role Cop investigating them.
As a Traitor is Mafia-aligned, it counts towards the Mafia's win condition. For example, in the situation of 1 Goon, 1 Traitor and 2 Townies, the game ends in a Mafia win.
So if that was your only argument, I'm not buying it. Try again.