He caught Harry's eye and Harry knew at once that Snape's feelings toward him hadn't changed one jot. This didn't worry Harry. It seemed as though life would be back to normal next year, or as normal as it ever was at Hogwarts.
What does the conjunction or mean in the following sentence?
Or is used here to express that what is previously stated is not the complete truth. We often do this in english.
The author is using a common phrase 'back to normal' in the context of wizards, thereby the possibility of normality is reduced. For that reason she emphasises this with the statement after.
The fighter was ready and waiting for the big fight, or just waiting.
Here the idea is that he is pretending to be ready however in actuality isn't. Its kind of like a mini contradiction.