The FIA has explained why Yuki Tsunoda was not allowed to unlap himself ahead of the final safety car restart at the Brazilian Grand Prix.

The incident evoked memories of last year’s controversial season finale in Abu Dhabi, when race control only allowed select cars to unlap themselves in order to speed up the safety car restart procedure and allow for a final lap of unimpeded racing between Max Verstappen and Lewis Hamilton.

In doing so, the race director at the time, Michael Masi, gave Verstappen a golden opportunity to secure the championship, which he duly took.

However, the reasons for the incident in Brazil were not the same as in Abu Dhabi last year and was instead down to idiosyncrasies in the layout of the Interlagos circuit.

Tsunoda was one of three drivers who were a lap down when the safety car came out, along with Alex Albon and Nicholas Latifi. He was leading that pack of three and was therefore the first driver to be recognised as a lap down by the FIA’s system when the safety car came out.

However, AlphaTauri decided to pit him under the safety car and in doing so he undertook the race leaders as he entered the long pit lane entry at Interlagos. When the drivers crossed the start/finish line, Tsunoda registered ahead of the pack and therefore unlapped, even though he then joined the middle of the pack one lap down after his pit stop.

When the safety car procedure reached the point at which lapped cars could overtake the train, Tsunoda was showing in the system as already being unlapped and therefore was not permitted to do it again.

“Race Control checked this was correct with F1 Timing and they confirmed that only Car 6 and Car 23 could unlap themselves,” an FIA statement said. “While this is a very unusual scenario, there were no systems or procedural errors — it is one of those unpredictable scenarios that can happen and there are no immediate changes that need to be implemented.

“This will of course be discussed at future Sporting Advisory Committees as part of the normal review procedures.”

Source: www.espn.com