The bug

Bees become angry when a Creative player harvests honey from a bee hive or nest, either by shearing it to get honeycombs, or by getting honey out of it by right-clicking with a glass bottle.

To reproduce

1. Switch into Creative mode
2. Run /setblock ~ ~ ~ bee_nest[honey_level=5] (alternatively, bee_hive can be used)
3. Place some flowers
4. Spawn some bees
5. Wait for bees to enter the hive or nest
6. Shear the hive/nest or right-click with a bottle on it
   → The bees inside of the hive/nest leave it and are angry