Imagine that Rose makes that tackle against Dzeko, and Mariner gives the corner (as he initially signaled before conferring with his AR.) How would that game look? Big picture: the score might have been different but Man City still get the three points.
But for me, I would've heard the same TV announcers assuring me authoritatively that the referee had got the difficult call exactly right. They would have shown the same replays from the same variety of angles and would have told me that it's a clean, fair tackle and that it was never a penalty.
This is hypothetical; it isn't provable, but I'm certain that's how the TV guys would have handled it, and it diminishes my enjoyment of the TV broadcast. I believe that the TV announcers know more about soccer than I do, but when they voice these assurances in the face of unconvincing (at best) evidence it casts doubt on everything else they say.
They're clearly trying to pre-empt conjecture or criticism of a dubious decision, and there's no need for it. The telling sign is the certainty of the assurances, which are at odds with the ambiguity of the evidence. Even with several cameras and slow motion, that call could have gone either way. These things happen and referees try to get it right. They make judgment calls, quickly and decisively, sometimes with scant evidence. This makes the game proceed and it's necessary, but they're not always right.
My quarrel isn't with the referee's decision. It was a coin toss; he called it a foul. It's a good topic for discussion; I object to the assertion that he was objectively correct.