The referee Mike Dean ignored an apparently elbow in the face that had been attacked by Ayoze Perez that had been a penalty and a red card.
He previously sent the Newcastle's DeAndre Yedlin to prevent a clear play opportunity, but Benitez reported that Jamaal Lascelles was close enough to interact.
"It was the key for the game, the red card and the elbow on Ayoze Perez," said Benitez the BBC.
"We need the VAR, and this stuff would have changed it all." How can you explain these decisions to our fans? "
Perez said the referee had told the ball that he was in sight.
Although the training of Yedlin, Benitez was likely that Lascelles was in an obligation position when his American team material Diogo Jota returned by the shirt.
"He was close enough to come over," said the Spaniard experience. "You can assure me that the player in the corner of the box can score at any time in the top corner, not a red card.
"We have lost three points today and we have to win violence."
In the meantime, Newcastle had to show their visitors to the top 10, nine points for them after a second win in five days after Chelsea's defeat.
Manager Nuno Espirito Santo felt his team was lucky. "We have not done the best performance," he said.
"We were not our winner or the possession of the ball, the red card changed the game, we were happy to make it at the end.
He denied the challenge of Willy Boly to Perez, but "a string of 'ball.
"It was a great game at the time we're all, everyone thinks that everything was left (Chelsea), but that's not true." (Message by Steve Tongue; edited by Martyn Herman)