So I've discovered this neat website: http://jsconsole.com/
basically you start with the command :listen and it starts a remote debugging session. You will get a session ID which you can use by inserting the following script into your page
When you visit your page now with the device experiencing the bug, you can access the console log from your development browser.
Now with some good ol' trys and catches you can start locating the source of the error.
//execution of a chunk of code
console.log('caught error in a chunk of code');
Here's a short intro by Remy Sharp http://www.youtube.com/watch?v=Y219Ziuipvc