[BrianG]

Chances are you vented the main three caps. That is easy to tell simply by opening the ESC and taking a look at them. If the tops of the caps are dome-shaped, then they are bad. Or, you could have blown something else, like a diode, TVS device, etc. Even though the ESC still "works", I would still send it in. Something burned up, and your ESC might not handle loads as well as it used to. The ESC might heat up more, or just not be reliable.