I know it's city so the hate against them is real and often justified, but that mistake was pretty horrendous. It's not Liverpool Spurs level of horrendous but it's right up there with some of the most egregious this season.
Players shouldn't mob refs though, won't help anything but it's got to be hard to keep your head in a situation like that.
I'm not really saying we should feel sorry for them. Personally, as a relative neutral, I think it's shit when it happens to any club, detracts from what was a decent game and furthers the narrative of how inconsistent refs are.
Like I'm no fan of Liverpool, Klopp especially has always pissed me off, but they were fully robbed and again it stained what was a good game. I'd never celebrate these sorts of things regardless of who it happens to.