(As of Debug Screen)
Java: 1.8.0_25 64bit
CPU: 4x Intel(R) CoreTM) i3-4130 CPU @ 3.40GHz
Display: Intel(R) HD Graphics 4400 4.3.0 - Build 18.104.22.16831
If an arrow is fired and lands on top of someone in creative mode, the arrow will break after a second.
To quickly reproduce said phenomenon:
1. In survival mode (so that the arrow is collected into inventory upon breaking, which makes the bug easier to observe), fire an arrow upward (not too far, as the arrow may veer off course laterally)
2. In creative mode, let the arrow hit you.
What should happen is that the arrow will simply bounce on the player, like arrows fired at the side of a creative player. However, it ends up breaking instead. This could, however, be intentional, as otherwise it would bounce forever.