Champions League: Rules expert explains game-changing 'errors' in Real Madrid's comeback over Bayern Munich

In one of the most epic Champions League semifinals in recent memory, Real Madrid produced another late UCL comeback, scoring twice in the final minutes to beat Bayern Munich 2-1 at the Santiago Bernabeu. It was Joselu who came off the bench for a brace, seeing the Spanish club advance 4-3 on aggregate, and they'll take on Dortmund in the final on June 1. 

But it wasn't without massive controversy.

As Bayern pushed forward in need of an equalizer to force extra time, defender Matthijs de Ligt found the back of the net with a brilliantly struck low shot from inside of the box. The only problem? The assistant referee put his flag up and called offside on the long ball preceding the Dutch defender's shot. De Ligt and teaMMAte Noussair Mazraoui went up for a long ball into the box and appeared onside. Instead of keeping his flag down and letting the play continue, the assistant referee called the offside, the ref whistled it, and the play was called dead. That meant that it could not be reviewed as Real Madrid players stopped playing before the shot went off. 

De Ligt and Bayern Munich manager Thomas Tuchel said the assistant referee apologized after the match with the coach calling it "disastrous" and "like betrayal" in an interview with TNT Sports.  

CBS Sports rule analyst Christina Unkel broke down the controversy on the Champions League Today Post-Match show and said there were multiple mistakes by the crew of Szymon Marciniak, Tomasz Listkiewicz and Adam Kupsik:

"Unfortunately, there are two officiating errors that occur here," Unkel said. 

"Here, he [Mazraoui] is not in an offside position, so we don't even have to get into discussion about whether he interfered with play. But, we have the first error by the assistant referee in raising that flag, which goes against the direction of holding that flag, especially where the attacking phase of play and it has not yet finished. And then we have the second error by the referee in accepting that recommendation by the assistant referee and blowing his whistle instead of saying, 'Thank you, I see you. I'm going to hold my whistle until this play goes out.' And this is very surprising. This isn't some of the best in Europe, this actually would be considered the best [refereeing crew] in Europe. This Polish trio, having refereed Champions League final, having just done the men's World Cup final. It was a very surprising decision by both the assistant referee and the referee which goes to an oversight in detail and attention at these critical moments.

"So it was not a good day for the third team today. "

Unkel went on to say that we could possibly see them punished in terms of future assignments of big games.

"It's never a good day when the discussion truly is about a clear, critical error by the refereeing crew. As we know, we call these key match incidents, game-changing decisions ... It doesn't sit well, not just only for that officiating crew naturally, but it doesn't sit well for the whole referee community, especially when we have three different layers of technology that can prevent us from making these types of mistakes," she said. 

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