The bug

When you throw an item with the associated key, the animation of the "right click" (like when you click on a button for example) is played.

How to reproduce

1. Pick an item in your hand
2. Press your key to drop the item
3. Look carefully at the animation of your hand

Examples

• Here is what it gives in 1.14.4: 1.14.4 Throw item hand animation.mp4
• Here is what it gives in 1.15: 1.15 Throw item hand animation.mp4