The pair made contact early in the race, leaving Gasly with diffuser damage that cost him downforce and lap time.
The FIA stewards looked at the incident, but opted to take no action. Explaining their decision they noted: “Car 10 locked its front right tyre into Turn 6 resulting in that car approaching the turn on a slightly different line at a slightly lower speed, which was obviously unexpected by the driver of car 44.
“Car 44 made light contact with the rear of car 10 in the turn. The stewards determine that no driver was wholly or predominantly to blame.”
Gasly, who a few laps after the contact was also left frustrated by a strategy call that dropped him behind team-mate Esteban Ocon, eventually finished 13th.
“It wasn't my day,” he said on Sunday. “Most of the damage was done when Lewis came at the back of my car and just destroyed the whole diffuser at the back of it. After that I was losing a lot of points of downforce.
“I braked late. I was surprised that he went even later - he would have gone straight if I wasn't there. I started to have a bit of front graining, I locked up a bit, but still made the corner.
“I think he just missed the braking point, and then basically ran up the back of my car. It was quite an impact, and it was just enough to break and lose some parts of the diffuser. So not great.”
Asked about the lack of any penalty, he said: "I mean, it's harsh, because on one side, I can lose 15-20 seconds of race time. Nothing, let's say, of my control. So on one side it's hard.
“On another side, yeah, he made a mistake and came in the back of my car. So it's a tough one. But it clearly cost me quite a lot today.”
Gasly insisted that the call that led to Ocon getting ahead was wrong, while conceding that points remained out of reach anyway.
“Obviously I wasn't happy with the strategy call,” he said. “And this will be reviewed and we made a mistake and I'm sure we'll learn from it.
“It should not happen, I think, the leading car always has priority. And we know it should not happen. I'm sure we'll learn from it. I'm sure it won't happen again.
“But then with all the downforce I was losing, [we're] talking four tenths a lap for 40 laps, maybe there was a P10 to fight for with [Lance] Stroll, but I don't think there was much more than that today. So, not the easiest race to finish the year.”
