You misundersand me. Failures are not due to inexperience. High failure rates are. If a single failure occurs in one out of eight launches, a double will occur once every sixty four. While I believe the Falcon is double fault tolerant, I don't believe for a minute that this is the first failure seen in a SpaceX launch. If they've seen only one other failure in their eight launches, their overall failure rate (resulting in loss of rocket, possibly cargo and crew) would be one in 64. That is nearly the failure rate of the Shuttle. With more experience, they may be able to lengthen their mean time to loss (MTTL) by improving the failure rate.