If you are an alliance player doing this quest, which requires stealthing through Stormwind to avoid the guards, you are flagged for PVP and all alliance players in Stormwind flagged as PVP are enemies and attackable.
If you are an alliance player doing this quest, which requires stealthing through Stormwind to avoid the guards, you are flagged for PVP and all alliance players in Stormwind flagged as PVP are enemies and attackable.