Williams’ decision to swap positions between Lance Stroll and Felipe Massa meant the team lost out to Stoffel Vandoorne in Sunday’s Malaysian Grand Prix.
Battling for position Massa was the first of the trio to pit with Stroll in a lap later and Vandoorne pitting a lap after the rookie.
But while Williams had been hoping that their decision to pit first would hand them the undercut on the McLaren driver, it didn’t work out that way.
Instead Vandoorne emerged just ahead of the tussling team-mates, handed vital tenths by Williams’ decision to let Stroll back ahead of Massa after the Canadian had been undercut by his team-mate.
“Since Lance, who previously had the lead, ended up behind Felipe after the pit stops, we felt it was correct to swap the places,” explained Williams’ tech chief Paddy Lowe.
“We also knew Felipe’s car was carrying some damage [sustained in first lap contact].
“Unfortunately, in the execution of that we lost a potential position to Vandoorne coming out of the pits.”