For what it is worth, this (information, not necessarily the source) is credible. I have intel that indicates this occurred in 2013 and that it low yield. Delivery will be the issue and there is a high probability that it will be neutralized. However, high probability is not definitive. Yes this is a potential game changer and a method of escalation for players other than Saudi Arabia as well. It should also modify perspective concerning the Shia – Sunni conflict.
I posit that this is why the Chinese have wadded in more heavily with Saudi Arabia, Yemen and Iran over the past 3 years. Saudi Arabia is posturing in general, if they attack in force on the ground in Syria then it will be more than posturing. Turkey is where more attention should be focused.