Lewis was leading the field until his pit stop and looked like he had enough of a gap when the Virtual Safety Car emerged. But Vettel took the opportunity to change tyres and emerged out front.
"We were trying to maintain the correct gaps and build enough of a gap to Räikkönen in order to avoid the possible undercut, while also have enough of an advantage to the Haas cars in case of a Safety Car," explained Toto.
"At that stage, everything was pretty much under control. We took a little bit of a risk putting Lewis onto the Soft tyre to go until the end, but it was the only chance to avoid Kimi jumping us.
"The pace was good and then we calculated the Virtual Safety Car gap that was needed. Our computer said it was 15 seconds, which was the necessary time in order for Vettel to jump us.
"We were always within this three or four second margin. And then suddenly the cameras showed Sebastian coming out in front of us. We have no explanation yet.
"It could be just a very unlucky situation that Sebastian was making it into the pits and accelerating between the two Safety Car lines. I don't know, this is just a hypothesis at the moment.
"Therefore, he would have lost much less on VSC than Lewis, who had to brake pretty hard in a high-speed zone. The software or system we have been using for five years just gave us the wrong number."