We've added the OnError event as well as the StartP method, they will be available with the next update.
We didn't add a property/method to interact with the torch directly because of the limited support. Apart from that, we were not able to trigger the torch for all camera modules on the mobile device we tested with, which means not all modules are capable of accessing the flashlight from the browser.
However, here you can find some code snippets that can get you started. It includes checking the currently selected device for the torch capability and turning the flashlight on and off: