In the 'Cube' demo, import the prefabs from the 'Taps' demo and place them in front of the RenderToTexture Camera. Play and try tapping the cubes, it will always be recognized as a LongPress Gesture, however tapping the table works. I've had this problem when I wrote my own similar code. It seems that it could be Unity being too slow.
I've shared one from a demo I did in November, but have since adopted your method as it is much better.
https://drive.google.com/file/d/0BwAC6q7_gz1QYURQQ0ozeEVmaUE/view?usp=sharing