Spot-kicks were central to the 1-1 draw between the two sides in Wednesday's (29.04.26) first leg - with Viktor Gyokeres and Julian Alvarez converting from 12 yards for the Gunners and Los Rojiblancos respectively - but the Arsenal boss was angered by referee Danny Makkelie's decision to reverse a spot-kick given for a foul on Eberechi Eze in the closing minutes after consulting the technology.
Arteta told reporters: "In the manner that we conceded the penalty, we were disappointed. In the Premier League, it’s not a penalty, but here I have to accept that this is handball.
"But what I’m incredibly fuming with is how the hell the penalty on Eze gets overturned in the manner that it happened when there is no clear and obvious error? And this changes the course of the game. And at this level, I’m sorry but this cannot happen.
"When a referee has to watch it 13 times, what is clear about that? It’s impossible and we are all fuming about it. We need to apply the rules.
"When you have fought so hard for nine months to be in this position, that goal could have completely changed the course of the tie. And it cannot happen. I’m sorry. We put so much on it. So, so, so much on it. This cannot happen."
Asked if he would take up the decision with UEFA, the coach said: "I think that it’s up to the club to decide the best thing to do. Now they’re not going to give us a penalty. That’s gone. And that’s it. That’s over."
Despite his anger at the refereeing, Arteta is confident that Arsenal can reach a first Champions League final for two decades in next week's second leg on home soil.
The Spanish manager said: "I’m very proud and I said that to the boys, the way we handled the context for nine-and-a-half months is just remarkable, and I really value what they’ve done because I’ve seen some of the best teams in the world here fall apart and concede three and four.
"We didn’t get the result that we wanted. We wanted to win it. But at least it is in our hands, in front of our people. We want to be in that final and in a week’s time we are going to have the opportunity to do that."