People do survive sarin exposure. Many more incidents can be found in a search.
Recently reported:
Turkish minister of Health says it has been confirmed from medical tests that Sarin gas was used. (reported in on Swedish news sites from AP).
Of course Turkey is not an impartial bystander, but this will be considered the last word on this matter.
As I have written elsewhere I am very sceptical, but then again the photographs, the videos from the hospital etc may be (bad) propaganda, and in reality, though not filmed, Sarin may have been used.