I have read the NTSB Executive Summary. As far as I have seen, the full report has not yet been made available.
The claim made by the report is the accident was the result of human error because one of the pilots unlocked the feather prematurely and that the actuators that control movement of the feather were overcome by aerodynamic forces (while going through trans-sonic speeds) and the feather moved. Deploying the feather is a two-step process, unlocking, which one pilot can do, and commanding it to move, which require both pilots to take action.
What I didn't see in the Executive Summary was whether Scaled Composites expected the actuators to be able to control movement of the feather while the vehicle was going trans-sonic.
Just after the accident, there were statements attributed to Scaled that the actuators should have been able to hold the feather in position after it was unlocked. If the people working on and with the vehicle thought this, how could it be human error for the feather to be unlocked when it was?
If it turns out that those earlier statements were incorrect and Scaled knew that it was a bad idea to, say, unlock while going through trans-sonic, then the Executive Summary should have indicated that. I just find it odd that it doesn't say anything about what Scaled had communicated to its pilots about the capabilities of the actuators for the feather once it was unlocked.