Red Bull technical chief Adrian Newey admits it was "heart-in-the-mouth stuff" over the safety of his two drivers during Sunday's Belgian GP.
Newey felt Sebastian Vettel and Mark Webber's safety were under threat due to the blistering to the option tyres. In the lead-up to the race at Spa, Red Bull wanted to replace the rubber their drivers used in qualifying after witnessing blistering on the outside shoulder of its front tyres. The request was denied though and Red Bull responded by pitting both drivers very early during Sunday's race.
Although the tyre issue failed to stop Vettel and Webber from finishing 1-2, Newey admits he was worried about the duo's safety.
"Pirelli were telling us after qualifying that our tyres were very marginal and they wouldn't say whether it was after half a lap or five laps, but they were going to fail," he is quoted in The Telegraph as saying.
"I have to say it was one of the scariest races I've been involved in, it was heart-in-the-mouth stuff, as first and foremost our duty of care is to the drivers' safety.
"And trying to make that call in making sure the car was safe, while not handicapping ourselves from a performance point of view, was quite a difficult judgement to make.
"Frankly at the end of the race I was very relieved that both our drivers were safe."
Pirelli motor sport chief Paul Hembery has hit back and insists Red Bull were at fault as they were running camber outside of a recommended four-degree limit laid down by the Italian company.
"We've never had a safety issue. It was created by two things - one, the lack of running on Friday (because of wet weather) and, two, going to the limits of our recommendations," Hembery said.
Newey though replied: "Obviously if we had known there was a safety concern about it, we wouldn't have done it..."