In the touch object you have : Device orientation supported
True if the device supports orientation detection (compass/tilt).
Run a simple application that will give you the value of this condition:Example application
I'm not sure though that this is a very good practice, as I test this application on my FF on desktop, and it tells me that orientation is supported. I don't have peripheral to use it though.
Anyway, test it on your Ipad, it might give you a clue.