Video Game Mafia

[Ryanderman]

But Nikose has a vig-like ability that's much more useful to the town than your mafia-immune-ness.

Unless this:

Nikose later retired and decided that he was done with using his hands to kill, and left only to vote.

means Nikose could only kill once, and he wasted it on killing a powerful town aligned role simply because he doesn't take the game seriously. In which case, yah, the BG should protect you.

EDIT: for this

Hmm, it is true that things are a little more complicated now. There is a WIFOM situation now, but there wasn't before, because there was only one proper course of action for the doc to take.

Not necessarily. If it was a foregone conclusion that the BG would protect Roy, the mafia would naturally target someone else. So it needs to be left unknown who the BG will target. There is just as much reason for the BG to protect someone else as there is to protect a known townie.