Reply To: Motion Sensors on Shabbos

I would think that there is an obvious Chiluk between if walking in front of the sensor flushes the toilet and if leaving being in front of the sensor flushes the toilet. Leaving the sensor Mistama is a Grama. Walking in front of the sensor, according to R’ Shlomo Zalman (and what seems the Pashtus) is a Ma’aseh and probably a P’sik Reisha D’nicha Leih (you really don’t want that stuff sitting in the toilet) and you would probably have to stay there all Shabbos (or try rolling out under the sensor if you know exactly where it is).