Referee Jon Moss appeared to blank Jurgen Klopp after Liverpool's 5-0 thrashing by Manchester City on Saturday.
The Liverpool manager went to offer a handshake towards the referee, only for Moss to carry on walking away.
When Moss did turn around, Klopp's offer was withdrawn as he walked away with a look of frustration on his face.
Moss had played a key role in the game when he dismissed Sadio Mane in the first half for catching City goalkeeper Ederson with a high boot.
"It was an accident," said Klopp afterwards. "The situation I think everyone knows he didn't see the goalie. There was not one second he looks on the goalie. He just wanted to get the ball as soon as possible. Hopefully the goalie is not seriously injured."
Hit play on the video at the top of the page to see the incident between Klopp and Moss.