The Norwegian manager came in for severe criticism and was put under pressure following the cup defeat in 2016.
Three days after the loss it was confirmed Deila would leave at the end of the 2015/16 campaign.
Looking back on that success for Rangers, then manager Waburton revealed how he believed the reaction towards Deila, who guided the club to two Premiership titles and a League Cup, to be “shocking” and “unjustified”
“I saw some of the treatment of Ronny Deila going into the game as a fellow manager,” he said. “I just thought some of the words written about Ronny were shocking.
“I knew when that final whistle went, of course you saw my reaction, but there was a moment where I stopped and thought ‘he is going to come in for so much inappropriate and undeserved abuse almost from the media’.
“I really felt for him. I genuinely mean that. He came in for some torrid headlines which for a man who brought so much success were fully unjustified.”
Deila has since gone on to manage Vålerenga and New York City who he led to MLS Cup success.
“He showed he is a quality manager and a class act,” Warburton said.
“There is going to be a winner and a loser in a game like that, you can write all the headlines you like and you can be on both sides of the coin but he didn’t deserve that. Some of the stuff written about Ronny building up to the game and post-game would never be tolerated down south.
“There was a joy and elation for what it meant to so many people on the blue side of Glasgow and around the world. I knew that and was hugely proud of what the players had done and for the fans but there is that other side of me that knew he was going to come in for some shocking headlines. Fully unjustified and fully undeserved.”