An oversight from Max Verstappen after the Red Bull driver's pit stop in Sunday's Monaco Grand Prix forced the Dutchman to race in the wrong engine torque mode for most of the race.
Honda's procedure required Verstappen to change from 'Torque 12' to 'Torque 6' as he exited the pitlane but an unsafe release by his team and the subsequent contact with Mercedes' Valtteri Bottas distracted the Red Bull charger who then forgot to switch settings.
The change could only be made in the pitlane, not when the car was back out on track running at full speed.
Honda's Toyoharu Tanabe told Motorsport.com that a bit of remote tweaking of the engine's parameters allowed to slightly decrease the negative impact of the mishap, but ultimately Verstappen's performance was still hindered by the inability to revert to a standard engine mapping.
Verstappen's contact with Bottas had obviously upset his immediate focus.
"Once on track you're stuck with it and we only did one stop," said Verstappen.
"Normally I would always go back, but of course with the touch, looking in the mirror all the time, and then I think the team were also a little bit shocked with the whole thing, they were also checking for damage.
"Normally they remind me but obviously it's my job to still do it. I also forgot with all the hectic scenarios."
Honda applied more parameter changes over the course of the afternoon, but Verstappen was left to contend with the issue on his own while battling race winner Lewis Hamilton for the lead in the closing stages of Sunday's event.
"I had massive lag on the first couple [of laps], I can't say the exact number, but quite a lot of percentage of going on the throttle," he added.
"So I had nothing, and then the power kicked in. It wasn't nice to drive but I managed to drive around the problem."