The nature of causality is controversial, but in my opinion it should be understood as a feature of the second law of thermodynamics. That causes precede their effects is an empirical law, not a logical necessity. Time turners can violate this in certain ways, but they don't throw it out entirely.
As you look through the block universe, you can observe various features corresponding to causality: the increase in macroscopic entropy, the expansion of radiation, the human creatures inside that remember the past and plan for the future. The block universe model doesn't eliminate causality; it is a physical feature within that universe.
This is a new thread to discuss Eliezer Yudkowsky’s Harry Potter and the Methods of Rationality and anything related to it. This thread is intended for discussing chapter 116.
There is a site dedicated to the story at hpmor.com, which is now the place to go to find the authors notes and all sorts of other goodies. AdeleneDawner has kept an archive of Author’s Notes. (This goes up to the notes for chapter 76, and is now not updating. The authors notes from chapter 77 onwards are on hpmor.com.)