Ryan Hedges. The Welshman clipped the heel of Alfredo Morelos after letting the striker get goalside, receiving his marching orders as well as conceding a penalty.
The contact was accidental but under the IFAB laws of the game only an attempt to play the ball sees a red card reprieve when the offence is denying a goalscoring opportunity.
Aberdeen boss Derek McInnes revealed that John Beaton had explained the decision, explaining he had no choice but to send off the 24-year-old.
Read more on dailyrecord.co.uk