[johnrobholmes]

You punched the throttle on 4s with a motor much larger than the ESC is designed to take. I doubt it was the BEC that smoked, although it is possible. In the instructions it says 3s max with the 4600 motor (which is quite small). They do write instructions for a reason these days, did you take the time to read them?

It doesn't surprise me at all that it smoked. What surprises me is that you were going to pass your clearly out of warranty action as a factory defect.