Daniel Ricciardo says Lance Stroll should have been more alert and focused on the cars in front after being hit by the Aston Martin driver in the Chinese Grand Prix.

Stroll ran into the back of Ricciardo as the field bunched up at the hairpin ahead of a safety car restart, pushing the RB into the air and damaging Ricciardo’s diffuser. Ricciardo had to retire soon after due to the amount of damage, and Stroll was given a 10-second time penalty that the Australian believes was justified given what he believes was a lack of concentration.

“It’s a restart, so we don’t know what the leader is going to do,” Ricciardo said. “So you have to be as kind of vigilant as ever, and just be prepared for any situation.

“I could see it was obviously bunching up into the hairpin, so everyone is backing up. But then obviously how hard he’s hit me, and pretty much put half his car under mine, it wasn’t a small lack of judgement. He was miles off. So yeah, that, for me, it’s not an excuse.

“I think what’s frustrating is that I watched his onboard, and he’s not even looking at me. You can see his helmet, he’s looking at the apex at the corner. I don’t know why he’s not looking at the car in front, unless his eyes are doing something funny. It looked like he wasn’t looking at me. I think it shows how hard he hit me. He was clearly focused on something else.”

Stroll himself believes his penalty was unfair because he attributes the cause of the incident to the car at the head of the queue that bunched up, which in this case appeared to be his Aston Martin teammate Fernando Alonso.

“Concertina effects,” Stroll said. “So someone braked at the front of the pack, I don’t know who. And then everyone stops. The car in front of me just stopped from like 60 to zero, so a really stupid incident. It was one of those.

“I think (the penalty) is just because of the fact that I hit the guy. But someone hit the brakes and caused the concertina, I don’t know who. I got a penalty because of the end result that I hit Ricciardo, but it’s not like everything was normal and I just slammed into the back of him. And there was a really odd concertina effect that I would have liked to see the stewards take into consideration maybe a little bit more.

“We’re going 60 and then started to slow a little bit for it, and then zero all of a sudden. It’s just a little bit wrong place too, I was in his gearbox kind of thing and ready for the restart, and just very unlucky. We were having a good race so then so it’s a shame.

“If someone didn’t hit the brakes in front, there wouldn’t have been any concertina effect, there wouldn’t have been any issues. I really think it was one of those stupid incidents.”