A man trying to walk into a restroom today will still be stopped. Men cannot go into women's restrooms, only women. If you see a man walking into a restroom and you think you should say something, then say something or do something. You won't get in trouble. If you happen to stop a woman who looks like a man you'll likely be embarrassed, but does that matter if you think someone is in danger? She might get mad at you too and call you names, but again, is that important if you think someone was in danger?
The North Carolina law forces some men to go into the women's room, and it forces some women to go into the men's room. How are you going to react when one of those men has to -- by law -- walk into the women's room?