Marussia has revealed that Maria de Villota's testing crash two weeks ago was not caused by a technical problem.
As the 32-year-old Spanish test driver remains in a Cambridge (UK) hospital with serious face and head injuries, her employer Marussia said it has completed a "detailed investigation" into the cause.
De Villota was at the end of the first installation run of a day of straight-line aerodynamic testing at Duxford airfield when the 2012 car surged forwards and crashed into the loading ramp of a truck.
Marussia team boss John Booth said on Monday the team is "satisfied that the findings of our internal investigation exclude the car as a factor in the accident".
The obvious implication of the finding is that the incident was caused by driver error.
But Marussia said in its media statement that, although de Villota was making her team debut, Duxford was actually the fourth time she had driven an F1 car.
A team insider is quoted by Germany's Auto Motor und Sport: "Sometimes it's harder to drive a (F1) car slow rather than fast."