When riding a horse, the player can mine, dig, build, fight, shoot, craft, smelt, enchant, repair, jump high, run fast, fall far, scoot around in lava, and scale terrain with ease. The only feature currently unimplemented is being able to sleep with your horse.
Steps to recreate:
1. Find, tame and saddle a horse.
2. Right click the saddled horse.
3. Be a God.
An optional step is to use a splash potion of invisibility on the horse. That way you can remove the inconvenience of having a horse head in your view and just concentrate on being epic.
... but no bug ...