Race stewards have decided not to take any further action on the eight drivers suspected of using DRS under yellow flag conditions during the 2013 F1 Grand Prix of China at Shanghai International Circuit on Sunday.
Sebastian Vettel, Mark Webber, Kimi Raikkonen, Valtteri Bottas, Daniel Riccardo, Jenson Button, Romain Grosjean and Max Chilton were all told that they would have to explain their use of the overtaking assist system after the race was over, and duly trooped off to the stewards office after the chequered flag.
But when the stewards reviewed the multiple incidents, they conceded that there had been a "degree of confusion" relating to the FIA's telemetry system, which has been hit by a series of problems since a new supplier took over provision of the service at the start of the season.
The system was once again partially disabled in China, which meant that the race officials couldn't centrally control the use of DRS by cars in the race as had been the case in previous seasons.
Moreover, there had been a delay of around a minute before drivers were informed via their steering wheel display unit about the deployment of yellow flags around the circuit, meaning that there was no way to be sure exactly what drivers had known at the time of any of the incidents being investigated.
In any case, the actual DRS use by the drivers took place along the main straight where a green light was displayed at the time, the stewards' ruling further noted.
The sheer number of drivers cited for illegal use of DRS under yellow was further evidence of how confused the situation was and how the drivers were likely not to blame for what ensued, the stewards concluded.
After the stewards' ruling, the race results for the third outing of 2013 will now stand unchanged.
Earlier, the stewards handed penalties to Red Bull's Mark Webber and Sauber's Esteban Gutiérrez for causing avoidable collisions during the race. As neither driver finished the Chinese GP, their penalties will take the form of multi-place grid spot drops to be served next weekend in Bahrain. (See separate story
However, the stewards did have one final ruling to issue after they deemed Red Bull to be guilty of the unsafe release of Mark Webber's car from the pit lane, with the right rear wheel not securely attached. The wheel came off the car before Webber could return to pit lane on lap 16 to have it attended to, the tyre then bouncing across the track right in front of oncoming traffic. Fortunately it did so without making contact with any of the cars.
"After changing the nose and all four tyres, Mark reported a problem with the right rear on the out lap, which had certainly left the pit lane fully torqued up," Red Bull team principal Christian Horner had insisted earlier. "The right rear then came detached from the car and caused Mark to retire. Until we get the car back, it's not possible to yet conclude the exact cause."
Pressed as to whether the problem might have been down to 'finger trouble' on the part of the pit crew member fitting the wheel, Horner said: "The report from the gunman who obviously had extra time because it was not a hasty time due to nose change was that certainly the right rear was secure and done up tightly."
The race stewards ruled that the tyre problem had been down to the team and fined Red Bull 5000 euros.