How we cite our quotes: Chapter.Paragraph or Chapter.Section.Paragraph (depends on whether or not the chapter had sections - some did not)
Quote #1
"She deserved it," Harry said, breathing very fast. "She deserved what she got. You keep away from me." (2.3.30)
Harry issues a rather harsh judgment against Aunt Marge here, and it's notably a judgment borne out of anger. The detail about Harry's quick breathing reveals just how agitated he is.
Quote #2
Hagrid wasn't a fully qualified wizard; he had been expelled from Hogwarts in his third year for a crime he had not committed. It had been Harry, Ron, and Hermione who had cleared Hagrid's name last year. (5.264)
The justice system in the wizarding world has definite flaws – it's an idea that got introduced in the second book, and we definitely learn more about it here.
Quote #3
"Miss Dursley has been punctured and her memory has been modified. She has no recollection of the incident at all. So that's that, and no harm done."
Fudge smiled at Harry over the rim of his teacup, rather like an uncle surveying a favorite nephew. Harry, who couldn't believe his ears, opened his mouth to speak, couldn't think of anything to say, and closed it again. (3.122-3)
Harry gets a crash course in politics here, as Fudge opts to not punish him for a variety of reasons, none of which have to do with actual rules or laws.