The Haas F1 team has been handed a five thousand euro fine for unsafe release during the Malaysian Grand Prix, after the front left wheel to detach from Esteban Gutierrez' car shortly after he had made a pit stop.
However the issue was not simply a case of the team rushing to put the tyres on, but an as-yet unexplained technical problem with the wheel itself.
"It appears that a mechanical failure led to the wheel being able to be tightly fitted to the car while not actually attached correctly," said the Stewards in the official announcement of their decision.
"An additional failure occurred in turn one under braking, but the wheel was still retained in an abnormal way until it appears that the failure of the rim blew the wheel past the retention devices.
"Having spoken with the Technical Delegate, the Stewards were satisfied that the retention devices operated within their required design limits.
"However, as some function of the design, part failure or fitting allowed the wheel to come loose on the track, which is considered a serious safety issue, the Stewards determined that this led to the car being released in an unsafe condition."
"We are not sure yet," said Haas team manager Guenther Steiner. "I've spent the last hour with the FIA to see what could have gone wrong, because normally the wheel doesn't go on the way how it went on, you know, so we sent everything back to Europe - to Italy - to investigate what actually happened because we are not clear.
"[The pit crew] got the bolt on the wheel and it was tight, but then it came loose somehow so it wasn't completely on when he torqued it but then the nut shouldn't go on, so we are not sure what happened. It's too early to jump to conclusions.
"That's why we went up to the stewards - we don't know, it wasn't the torque on the gun and we just don't know yet what's happened.
"[Possibly] something was broken before in the assembly, inside, so the wheel didn't go on complete. But we we don't know - we can't do the analysis here because we need all the car data to simulate all the various ways it could have gone right or wrong. Very strange."
Gutierrez himself was not penalised, with the stewards explaining that: "Having reviewed the audio from the car, the available data and spoken to the driver and team concerned, the Stewards were satisfied that the driver Gutierrez did not know that he was driving the car in an unsafe condition."
"I was pushing to the maximum and then under the virtual safety car I tried to come in to benefit from that, and when I approached turn 1 after the pit exit something broke on the car," the driver explained. "Unfortunately that was the end of the race. No indication.
"I just checked the videos and nothing looks strange. They're analysing what happened - hopefully we can understand it, because it's not nice."
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