For some odd reason, arrows will disappear if you shoot a player in creative mode. Their sound will still play if they hit the ground because it only disappears on the client. The person who was shot by the arrow will still see it, but not the shooter. This might also be the case with other players other than the shooter or the victim but it was not tested.

How to Reproduce:

1. Shoot an arrow at any other player in creative mode (weapon does not matter)
2. Let it hit the ground