He did so for the most reasonable of reasons: to avoid disqualification.
With Formula One rules stipulating that teams must use both tyre compounds for each race, Webber had raced all along only on the softs and needed to switch to the hards, and Red Bull's fate with Webber came down to either fourth place or oblivion.
"Fourth was ultimately the best we could achieve today," Christian Horner, the team principal, said after Jenson Button passed Webber late to snare the last podium spot.
The desperate but necessary strategy began with Webber's first pit stop when, Horner said: "We had a wheel nut issue and thereafter it dropped him behind Felipe Massa, so at that point" they chose a three-stop race, "the only opportunity take on and beat Massa and have a go at Jenson."
They took on and beat Massa but could not forge a lead wide enough to hold off Button once Webber had to visit the pits during the race's last fumes.
That time-consuming first pit stop, Webber said, "put us on the back foot. I got the car back onto the leaders, but we were out of position by then."
On the second pit stop, while everyone else went to the second of the tyre compounds, Red Bull stayed with the softs to "try and cut the race down to something different," Webber said.
"It was certainly worth a bit of a punt."
Said Horner: "Unfortunately there just weren't enough laps to pull out a big enough gap, but it was worth a go and Mark drove well," even if it ended with Red Bull being absence from the podium for the first time this season, and at a "track that's been so good to us over the last two years," Horner said.