If you search for "rabbit herding sheep" you will find multiple links on You Tube and to news organizations like CBS showing a cute little brown (dwarf?) bunny, herding a small flock of sheep.

The flocking behavior of sheep is well known so there is no surprise that they stay together when chased.

Is there any known habits or behaviors of pet rabbits that would make this a semi natural event?

Presumably if it is semi natural behavior, it could be recreated with little difficulty. If not then this is one very special little bunny.