Romain Grosjean admits his verbal attack on Marcus Ericsson in the wake of the Chinese Grand Prix "wasn't nice".
The Haas driver lashed out at the Sauber man after having to pit for a new front wing when he was damaged in contact at Turn 1 of the Shanghai race.
"It was the worst possible birthday," Grosjean told Canal in a post race interview. "That idiotic Ericsson hit me in Turn 1 and broke my front wing.
"He saw nothing, he understood nothing, I just think he should open his eyes."
However, days later and having seen replays of the incident, Grosjean admits his behaviour was uncalled for.
"I have seen the first corner incident again," he told Motorsport.com.
"Initially I didn't see it Toro Rosso cutting the track, so it wasn't as bad as I initially thought.
"It was more like a racing incident. He could have done it a bit differently but it doesn't really matter.
"On TV I said he was an idiot, which wasn't nice from me, it was probably from the emotion of the race."
Ericsson, though, doesn't sound like he's all that willing to accept an apology.
He told the publication: "It was unfortunate that his wing went off, but sometimes it goes like that.
"I was just surprised by his behaviour afterwards – the way he approached me screaming and calling me different things.
"Just because you are a good racing driver doesn't mean you can behave like that off the track. For me it is not very nice."