The main point sentence, lines 7-11, is a wonderful paraphrase of (E).
7-11: The goal of preventing harm to others ....
(E): The principle of preventing harm to others ....
7-11: would also justify legal sanctions against ...
(E): can be used to justify laws that ....
7-11: some forms of nonconforming behavior to which this goal (of preventing harm) might at first not seem to apply
(E): do not at first glance appear to be designed to prevent such harm
I mean ... I see the disparity you're asking about, but we can't expect them to give us a verbatim restatement of the main point.
"nonconforming behavior" just means "you broke the law / you didn't conform to it".
We're only seeing that language because of the 2nd sentence, where the legal theorists would say "you can't write a law that forces people to conform to a certain behavior if the behavior you're prohibiting, the nonconforming behavior, doesn't inherently cause harm to others."
So there's really no difference at all between 7-11 and (E).
This passage, like so many others, starts with someone else's point of view and then pivots into the author's main point (an "I disagree" type statement) using
but/yet/however.
OTHER POINT OF VIEW:
you can only call something a crime and criminally punish it if the underlying behavior would harm someone else.
if an act is intrinsically harmless or if the act only harms oneself, then you can't have criminal penalties against it.
You can't force people to conform to some rule if nonconforming wouldn't harm someone else.
AUTHOR'S OBJECTION / MAIN POINT (lines 7-11):
You're kinda right, but kinda wrong.
I agree, our goal is to prevent harm. But there are cases where you need to make a law against something that doesn't directly cause harm, but where harm would result if there weren't a law.
P2 ... "in many situations" ... [you need a coordinating rule because a lack of one would cause harm]
P3 ... "in some other situations" ... [you need a rule against 'self-inflicted' harm if it would indirectly encourage other people to inflict harm on themselves]