When Hannah is in the bathtub just before killing herself, we do not hear or see any water running. When the tub overflows as she bleeds out, we see the faucet running.
At about 47:40 when Zach checks his texts from Alex, the last incoming message is "Please call."
The phone is shown with a string of incoming messages from Alex on the right side with the newest incoming message on the left side indicating that it was an outgoing message.
The phone is shown with a string of incoming messages from Alex on the right side with the newest incoming message on the left side indicating that it was an outgoing message.
As Clay gives the tapes to Mr. Porter, he claims that everyone before Mr. Porter knows about what he did. However, Bryce also comes before Mr. Porter and Clay is skipping over him on purpose, so he knows Bryce can't know anything about Mr. Porter's involvement with Hannah's death.