Right, the 4g/day number is the amount that should be safe for any relatively healthy adult (minus whatever is making them take the medicine). I should hope it isn't too close to the number where you can cause permanent damage.
It's become fashionable to fearmonger about it lately, but I agree, it's safe to assume the makers wouldn't tolerate the liability that would come with a single extra dose above the given instructions causing that kind of harm.
