I don't have too much experience with LRP speed controllers, however I have witnessed them overheating on more than one occasion. Furthermore, they're very sensitive to moisture like all ESCs are. Now as I said I don't have much experience with LRP controllers, but in my experience with other ESCs, suddenly stopping, still being able to steer, and red and yellow lights is usually a warning of overheating, or.. Your motor could be faulty, I'm not certain how new or old your powerplant is so the validity of that statement is a crap shoot, ESCs have been getting more and more advanced, and (if this is the right term) more intelligent, so your controller could very well be saying "Crap, the motor isn't doing what I'm telling it to!" haha

I would suggest you contact LRP for exact information on their indicator lights, and when and why they show up.

Hope this helps!