I think it really just comes down to context...I don't have an even remotely ocker accent (in fact most people here tell me I have an English accent), but I don't think anyone has any trouble knowing if I'm calling someone a bastard (or any number of other swear words that have different levels of harshness depending on the situation) in an friendly manner, or if I wish them condemned to the fiery depths of hell (generally saved for the Blues come State of Origin time *grin*).