Probably since if I recall correctly one of the Force India guys or a driver from one of the low/mid tier teams had a 9.something G crash at Monaco this year and I don't think they went to the hospital. I'm betting Massa's crash during the race was like 12-15Gs.
According to this article on Alonso's incident, 1. He sounds fairly ok 2. The sensor goes off at 15Gs. But, they are saying the sensor wasn't properly attached, and so the reading was most likely incorrect. Doesn't change the fact he has been experiencing some degree of pain.
