Yes, exactly. If you're shot, a medic can (try to) save you, but that doesn't prevent you from getting shot. In terms of actual game-play, it would be easier to keep the game balanced if the wolf and mafia nights work exactly the same (ie, consider the medic as 'protective custody' or something), but I think it would make the game more interesting if the two factions were not identical.
Keep the wolves bite the same as it is now (x% chance of success, angel protects against), but make the mafia recruitment such that the medic doesn't protect against it, x% chance of success, but a failed attempt has a y% chance at taking out one of the mafia (perhaps the recruit has a gun already and doesn't like the mob...). I'm thinking x=50, y=25 for starters.