Zarco and Oliveira came to blows on the ninth lap of 20 during Sunday’s race while fighting over 12th position as Zarco attempted a move up the inside of The Loop.
Both riders were unhurt, and Zarco was seen apologising to Oliveira for his move.
A stewards report said the Frenchman was “found to be riding in an irresponsible manner causing a crash” and will therefore drop three grid spots at Misano.
Oliveira was critical of Zarco, saying he felt the crash denied him a chance of a top-10 finish.
“I think he was too optimistic about overtaking there,” recalled Oliveira. “It was a shame because I felt I was with a good pace, I was feeling good on the bike.
“I was just there controlling my tyres a little bit, I was not expecting at all someone would overtake me there. I was doing the corner and I just saw the bike come out of nowhere.
“I don’t know what he was thinking. He’s a two-time world champion with almost three years of [MotoGP] experience, he should know better what to do on the bike and where to do it, and at what time of the race.”
For his part, Zarco said: “I tried to overtake Miguel in that very slow corner, and I went into the corner thinking he would see me, because in practice I could overtake some bikes in that place.
“Unfortunately he saw me, but a bit too late. He didn’t have time to pick up the bike, and we were [going] so slow, so we touch and we crash. It’s a shame.
“I’m really sorry for destroying his race, because also for him it was a good race.”
Miguel Oliveira, Red Bull KTM Tech 3
Photo by: Gold and Goose / LAT Images