When Endermen are hostile, and they turn back to neutral, they make the stare scream sound that's normally only triggered by staring at them.

This seems to only happen if you're looking at or near their face the moment they turn neutral.

Easiest way to reproduce:

1, Go to survival and aggro an Enderman.

2. Make sure to look at his face once to trigger the stare sound before step 3

3. Look at his face while you switch to Creative-mode

= The Enderman will make the stare-scream sound again for no reason

This can also happen when you're fighting an enderman during the day and it teleports away and turns non agressive.