Errors thrown when using NetworkServer.ReplacePlayerForConnection()

Hi! I'm working on a project right now that gives 2D players the ability to take control of a vehicle. In a related forum post (http://forum.unity3d.com/threads/question-about-local-authority.333846/), I found that NetworkServer.ReplacePlayerForConnection() could be a viable way to give players authority over a vehicle object. I made a hasty implementation of this and soon realized that I needed my original player to retain authority as well - their ability to send commands related to their health would be lost by simply switching the player object for the connection to the vehicle!

Today I've taken a second crack at the problem. I made a second "dummy" player (with its own playerControllerId) that exists on each client. This "dummy player" is a prefab carrying a network identity and no render component. I then made it so that NetworkServer.ReplacePlayerForConnection() replaces the authority on the dummy player's player controller over to the vehicle when the "real" player enters the vehicle, and leaving a vehicle gives authority back to the "dummy player". I'm getting a strange error thrown with this implementation:

The error above runs as soon as a client player enters a vehicle.
If the player exits the vehicle this next error is thrown:

If a player gets in the vehicle a second time, the error above is thrown every frame. A related RPC (which tells the "real player" object to lock their movement) is running at the same rate, over and over. Any ideas as to what's going on here?

 

A little more information: It looks like I have a warning showing up when I spawn the dummy player about a "Duplicate Observer". This warning comes back up any time I get in or out of the vehicle. Another warning appears just after saying that the "playerControllerId is higher than expected" at a value of 1. I tried changing that to 4, and the error still shows up. I know that the dummy player is spawned through a command on the real player, and I opted not to use ClientScene.AddPlayer() as I wanted a different player object for the dummy. Is that part of my trouble?

 

Thanks for the quick reply!

Taking a read through that forum link and through the beta release notes (http://unity3d.com/unity/beta/unity5.2.0b1), I saw part of a bullet point that still left me confused:

Does this mean that whole clients only have authority on one object, or player controllers only have authority on one object? If a whole client only gets authority on one object, isn't this "dummy fix" still null and void? Do I really have to route the original player's health and commands through the vehicle?
Edit: Or did that mean that an object can't have multiple client owners, but clients can own more than one object (so long as it is not already owned by another client)?