The centre-back was sent off for a foul on Vicente Besuijen that led to Bojan Miovski opening the scoring from the penalty spot, and from there Aberdeen didn’t look back.
Ross McCrorie netted before Besuijen fired home a second spot-kick, Miovski netted again and substitute Ryan Duncan put the cherry on top with a late fifth.
Aberdeen manager Jim Goodwin said “It has a massive impact on how the game pans out thereafter. I thought it was actually an even game 11v11 with both sides having good spells.
“It’s not always as straightforward as the boys have made it look to break down 10 men and the players deserve a lot of credit.”
The manager was less happy that Miovski handed Besuijen the ball for the second spot-kick, and commented: “I wasn’t in the loop on that one. It isn’t something I would have encouraged before the game. He is our penalty taker, and though I love that he wanted to give his team-mate a goal, that’ll not be happening again.”
He said: “We looked value for money 11v11 but we make an absolutely stupid mistake. It was really naive but Jack needs to deal with it better, and we need to learn from the mistakes.
“I made a number of changes at once to protect players on bookings and those who will be involved on Wednesday night, but I have to admit I got that one wrong.
“We made the changes at 3-0 and it finishes 5-0 so I have to take that one on the chin.”