The former Celtic striker branded the linesman during their Scottish Cup loss an 'idiot.'
Celtic lost 3-2 to the Scottish Premiership side after extra-time, meaning their hunt for a first domestic treble since 2001 came to an abrupt halt.
The loss has led to understandable disappointment, with the Bhoys being criticised for missing a huge opportunity to win all three Scottish trophies.
Deila's men were, however, robbed of a blatant penalty after a clear Josh Meekings handball on the line and Sutton feels the official who missed the incident 'must be an idiot.'
He said: "There is no way he could have thought that ball hit the player on the head, he must be an idiot not to see it. It's just ridiculous."
The decision aside, Celtic still produced a flat performance when it mattered most - a very similar one to that of their 1-1 draw with the same opposition the previous week.
But Sutton feels the perception of Deila's debut campaign at Parkhead won't alter as the Norwegian has made the Hoops 'stronger' throughout the season.
He added: "I'm not saying that changes the perception of what Ronny Deila has done. As the season has gone on, Celtic have got stronger - but you have to say it's a chance to win a treble missed due to not just a poor decision but an awful one."
Celtic travel to Dundee on Wednesday night, before facing five more fixtures that will decide whether they end the season as double winners or merely League Cup champions. Five points clear with a game in hand, they're certainly in the driving seat...