The Bhoys secured a 2-0 Scottish League Cup final win against United to hand Deila his first trophy as Celtic boss, thanks to goals from Kris Commons and James Forrest.
But Forrest was also involved in the incident that displeased Hoops boss Deila, after he missed from the spot when his side were two up.
The Norwegian wasn't bothered by the miss itself but rather the manner in which Celtic's players, including Forrest and John Guidetti, argued over who should take the penalty.
“It looks like it was the first to the ball but I don’t like that they argue about that. It is stupid. That is not the team spirit I want. We have to learn from the situation," Deila said rather bluntly.
“John Guidetti was unhappy, for instance, and there is a lot of emotion in these situations with strikers wanting to score goals."
Indeed, the Celtic star - who was once again in superb form at Hampden Park - feels it is a good sign that there was an eagerness to take the penalty. Johansen even joked of his surprise that goalkeeper Craig Gordon wasn't staking his claim...
“It’s a good thing that everyone wants to take it," the Norwegian said. “It’s a cup final and we’re leading 2-0 and everybody wants to score. I was actually surprised that Craigie [Gordon] was also not up there wanting to take it. That’s normal.
"Jamesy took it and he missed but that happens sometimes. Everyone’s friends now. Sometimes you miss sometimes you score, the most important thing is that we won the game.”
Celtic will face Dundee United once again this Wednesday, this time during a Scottish Cup quarter-final replay.