The code only listens to mouse events when touch events are NOT supported. Just because touch events are supported doesn't mean there isn't a mouse (eg. Win8 laptops running Chrome, BlackBerry devices, normal laptops using browsers that support touch events even though no touchscreen hardware is present, etc.). See my G+ post for more details: https://plus.google.com/u/2/115788095648461403871/posts/6RqRCEVbqpC
The right fix is probably to ALWAYS listen to both mouse and touch events.