Mercedes boss Toto Wolff says it was "shameful" that debris left on the track during the Azerbaijan Grand Prix ended up costing Valtteri Bottas a Formula 1 victory this year.
Bottas had been leading in Baku with three laps to go when he hit a piece of metal left on the circuit after a clash between Kevin Magnussen and Pierre Gasly after a safety car restart.
The impact punctured Bottas's right-rear tyre, robbing him of what was a golden chance to win the race and top the world championship standings.
Reflecting on the 2018 season, Wolff said the puncture was one of the lowest points of the campaign.
"Baku for me was a shock," Wolff told Autosport. "I was very annoyed and very upset because of this whole manoeuvre.
"Magnussen vs Gasly was crazy, and should have been severely penalised.
"Then the debris being on the track from this shit fight, at this shit place [position] at the back of the grid costing Valtteri this win is shameful.
"It is shameful. This is one of the worst moments for me this year."
Wolff believes Bottas's season was defined by a run of bad luck at that stage of the year.
He had lost a likely win in China a fortnight earlier when a safety car bunched the pack, allowing Daniel Ricciardo to carve his Red Bull through the leading pack and win.
Bottas also came close to winning the second race of the season in Bahrain, and Wolff said he thinks his driver would have been transformed if things had fallen his way better at this time.
"If he would have won those three races, he would have been easily in the lead of the championship after Baku," he said.
"I think for a racing driver, not competing for the championship any more, if this is everything that you are in there for, it is very difficult.
"We have seen with Valtteri the two times when he could not drive for the championship any more and we had to back Lewis, because he had more points, you could see that there is a drop of performance.
"I think it affects every driver. So if he stays in the hunt, that makes a big difference."