Niki Lauda blames Lewis Hamilton "more than" Nico Rosberg after the Brit's mistake put both Mercedes team-mates out of the Spanish Grand Prix.
Hamilton led on Sunday off the line but was overtaken by Rosberg, who swept around him through Turn 1.
Trying to retake the position, Hamilton went for a move up the inside but put his W07's wheels on the grass.
Losing control of his Mercedes, he collided with Rosberg, shunting them both into the gravel and out of the grand prix.
Mercedes non-executive director Lauda was furious.
"Completely unnecessary I would say," said the triple World Champion.
"For both Mercedes to be out after one lap is unacceptable.
"Lewis was too aggressive to pass him, why should Nico give him room he was leading.
"It was a miscalculation in Lewis' head, I blame him more than Nico."
Toto Wolff, though, wasn’t so quick to apportion blame.
"We talked to both drivers, it is not a clear cut decision,” said the Mercedes motorsport boss.
"It is a very difficult situation for the team as we have lost 43 points after a huge effort in the last couple of weeks.
"But we let the drivers race and sometimes this is what happens. The stewards are going to make a decision and from our perspective not to blame entirely."