Aberdeen boss Jim Goodwin insists Livingston keeper Max Stryjek should have been red carded in the 2-1 loss at Pittodrie.
Goodwin also believes the Reds should have been awarded a penalty when Strjek struck winger Vicente Besuijen in the face at 0-0.
Instead referee Grant Irvine only booked Stryjek – with no penalty awarded.
Besuijen was also booked by Irvine.
Within a minute of that controversial incident Livingston went ahead.
Aberdeen are now only five points above the relegation play-off zone, with four games of the campaign remaining.
Goodwin said: “I saw the Livingston goalkeeper, he pushed his hand into Vincente while the ball was in play.
“By the letter of the law it should be a red card and penalty.
“I don’t like talking about referees, pundits and journalists have all discussed how poor the officials have been this year.
“I don’t want to add to it but hopefully it will improve next year.
“Some big moments and key decisions went against us.”
No discussion with referee Irvine
It was a disappointing defeat for the Dons, seeing out the Premiership in the bottom six for the first time since 2013.
Goodwin says he never attempted to ask for an explanation from the whistler.
He said: “I never went to speak to the referee, I don’t see the point.”
Red card for midfielder McCrorie
Aberdeen were reduced to 10 men late in the second half when Ross McCrorie was dismissed for a second bookable offence.
Goodwin said: “I thought for the red card it was a good 50/50, I thought Ross has got the initial contact onto the Livingston player.
“It’s a silly tackle when you are on a yellow card.
“The reaction makes the referee think it is worse than it is and it gives the referee a decision to make.
“He’s been really good since I came in and I hope he learns from it”