Nick Heidfeld was critical of Fernando Alonso after the double world champion crashed into him in second practice for the European Grand Prix, bringing the German's programme to an early end on Friday.
As the pair came into the final corner in the last 20 minutes of the session, Alonso locked up as he dove down the inside of the BMW, made contact and flicked Heidfeld's BMW in the air.
Heidfeld was heard to call the move 'stupid' over the team radio.
"Such a crash is really unnecessary during free practice," he said. "I saw him in the rear view mirror locking up his wheels and tried to open the door for him, but he went straight into me and I almost rolled."
BMW also ran new aerodynamic components and lightweight chassis for both drivers on Friday, which helped propel Robert Kubica to seventh in the times in the second session.
But the Pole believes that despite the introduction of a new engine cover and undertray, the F1.09 still has the same intrinsic flaws that had hit the team's competitiveness this season.
"We brought some new components to Valencia and tested these in both sessions," said Kubica. "In the afternoon we concentrated on evaluating the tyre compounds on long runs.
"For me it was a Friday without problems. The grip on the track is quite good and we were able to go at quite a good pace. However, we still face the same problems with the car we have had since the beginning of the season."