The Celtic boss gave his verdict on what looked like a terrible decision.
Ronny Deila quipped that Scottish football should consider seven referees instead of five after Celtic were not awarded a penalty for an apparent handball from Josh Meekings, according to the club's official Twitter feed.
But things could have been very different had Meekings been penalised after blocking Leigh Griffiths's shot on the line with his hand.
It was a moment that proved hugely costly for Celtic and Deila was understandably unhappy during his post-match press conference.
RD again on the handball: "We have five referees, maybe we need seven - one on each post." (MH)— Celtic Football Club (@celticfc) April 19, 2015
RD: "It’s hard for me to discuss this. A tough blow for me and the boys. We are very disappointed. We should have killed the game." (MH)— Celtic Football Club (@celticfc) April 19, 2015
RD: "Everybody knows that the game would have been finished. Referees make mistakes as well but this one is hard to take." (MH)— Celtic Football Club (@celticfc) April 19, 2015
Deila wasn't the only one that was angry, meanwhile, admitting that 'everybody' reacted in the same manner to the poor decision.
It is 'small details' like the referee's failure to give handball that can determine a season, the Norwegian admitted, which is exactly what makes a treble so difficult for Celtic - and indeed anyone.
The Scottish Premiership now remains Celtic's only focus - but a double is certainly still something to be very proud of.