The failure of Nico Rosberg's Mercedes at the Singapore Grand Prix has given the championship advantage to teammate and race winner Lewis Hamilton - and it raised questions about whether Formula One's proposed new radio bans are a good idea.
Hamilton's victory raised him three points above Rosberg in the drivers' championship standings with five races to go. It is a thin advantage in points, but back-to-back wins could give an edge to a driver like Hamilton.
When Rosberg qualified only seven-thousandths of a second behind pole-sitter Hamilton, the stage was set for another epic duel between the Mercedes drivers in the night race around Marina Bay.
Rosberg's problems came to light on the formation lap and his car failed to get off the line for the warm-up lap, meaning he had to start from pit lane.
The issue was a broken loom in the steering column that affected the electronic connections to the steering wheel. That left Rosberg without fourth and sixth gears, plus there was no access to battery-stored power boosts and no way to open the rear wing on the straights.
The team managed to get the car started from the pits and Rosberg into the race, but he lasted only 14 frustrating laps at the back of the field before retiring.
''The toughest day of the year for me,'' Rosberg said. ''I felt so helpless. Nothing was working at the beginning of the race. It's just reliability, for the team, that's the area we need to work on, that's the weakness. They're flat out, but we need to improve somehow.''
Prior to retirement, Rosberg was receiving a barrage of messages over the radio about the operability of the car, and how he might improve it. And that raised questions about the practicality of a proposed ban on most radio messages about the car performance.
That rule was to have started in Singapore but teams complained, and the FIA delayed the introduction of the ban to the start of 2015. A ban on driver coaching - instructions on braking, acceleration, racing lines and the like - did start on the weekend, with no egregious transgressions.
Mercedes said Rosberg's situation showed that the proposed car-performance radio ban should be reviewed.
''A nightmare,'' Mercedes team principal Toto Wolff said. ''Can you imagine not being able to give any messages to the driver? Maybe the Singapore race, with all its ingredients, needs to flow in to any future direction on radio messages.''
The modern F1 cars, with their complex interaction of combustion engine with two hybrid power systems harvesting energy from braking and exhaust heat, require performance monitoring from the pits.
''These cars are so bloody complicated and there's an awful amount going on,'' Red Bull team boss Christian Horner said. ''I completely support getting rid of driving coaching through the radio ... but in terms of managing the power unit, they're so complicated that from a reliability and safety point of view, it's important (to keep radio messaging).''