The FIA has revealed that all of its systems functioned "correctly and according to the regulations" after a bizarre safety car incident with Yuki Tsunoda.
AlphaTauri driver Tsunoda was left marooned in the midpack during a late safety car period whilst Williams duo Alex Albon and Nicholas Latifi unlapped themselves.
The Japanese driver was splitting the Williams team-mates at the time, though only Albon and Latifi's numbers were posted within race control's 'cars may now unlap themselves' message.
This meant Tsunoda was consigned to finish last of those still competing, with both McLarens and Kevin Magnussen retiring.
The FIA upgraded its race control systems for further robustness after the lapped-car drama at last season's Abu Dhabi Grand Prix, and they confirmed they worked as normal at Interlagos.
But attesting to the "idiosyncrasies of the specific circuit and scenario", a spokesperson for the governing body detailed: "Car 22 [Tsunoda] was the first to cross SC1 [the first safety car line] following the deployment of the safety car
"On the following lap he therefore became the first car to cross SC1 line for a second time, which would normally trigger the systems to indicate he is eligible to unlap.
"However, at this time he entered the pit lane and was able to go faster than the train of cars behind the safety car. In doing so, he unlapped himself when crossing the control line in the pit lane.
"When he re-joined the circuit, the systems correctly indicated that he was again a lap down, however as he had already unlapped himself once, he was not eligible to do so again when the safety car period was ending.
"Race control checked this was correct with F1 Timing and they confirmed that only Car 6 and Car 23 could unlap themselves.
"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."
The issue is understood to have been placed on the agenda for the next Sporting Advisory Committee meeting.