Lando Norris was "shouting and swearing" after an incident with Sergio Perez in the Japanese Grand Prix under the Virtual Safety Car.
After Perez had hit Kevin Magnussen at the hairpin, the VSC was called to remove debris, with Norris running in second place, about five seconds behind race leader Max Verstappen.
However, as he rounded Dunlop Curve, Norris came across the slow Perez, and requested from race engineer Will Jospeh if it was possible to pass the Red Bull.
Article 56.6d of the Sporting Regulations permits a driver to overtake another under VSC conditions unless there is an obvious problem - just as a puncture.
There were no outward signs of distress to Perez, with Norris following the RB19 through the Degners, and the hairpin until the VSC finished as the two were rounding Spoon - but Perez moved across at this stage, with the two almost colliding.
Norris would go onto finish second, some 19 seconds behind Verstappen while Perez retired but the McLaren driver expressed he was unaware of what was going on as the team tried to figure out if he could pass Perez and not earn a penalty.
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Norris on Perez incident
"I have no idea. I don't know what… [I thought] he must have had a problem, right?," Norris told media including RacingNews365.
"But the thing is you can't overtake under the VSC unless it’s obvious the guy has a problem and I don't know what was going on, I didn't know if he had a problem, whether he was just backing me up.
"I didn't know and I couldn't take the risk of just overtaking him. He was going so slowly and then when we got the flashing dash for the VSC ending, he went into first gear and then I was on the outside of him because he was going so slowly, and then he almost crashed into me.
"So I honestly have no idea. I was shouting in my helmet. I was swearing quite a bit, but just got so confused, I didn't know what I could do.
"I [was] losing time to Max. The Ferrari guys were, I think, 1.4 seconds behind me after being I think 12s or 13s, so I lost 10 seconds.
"I didn't know what I could do at the time. If he has a problem, he should pull over and make it obvious that he has a problem.
"He didn't and therefore I couldn’t take the risk of passing under a VSC, so I have no idea
"I don't think it would have changed the world, it just made me stress for a little bit more.
"It would have been maybe just a bit better to put Max under a little bit of pressure at least, after that. I don't think we would have been quite as far behind.
"So yeah, a frustrating time, maybe I'll ask next time what you're allowed to do but I think I did the right thing so it is all okay."