Another interesting behavior I've seen regarding docking is when you are escorting a smaller freighter type (e100 or e200 usually) that is approaching its destination station - it will occasionally just start spinning around rapidly and gradually float away from the station it is supposed to dock with.
This doesn't happen all that often, and it generally doesn't last for more than 15-30 seconds before it recovers and successfully docks, but it does look quite strange.