I don't think Dias is just being dramatic, though. He's got a point about consistency – if Barnes pushes Donnarumma out of position without even getting a yellow card, that's not right. And what's with the difference in how fouls are called throughout the game?
And on top of that, Guardiola is having all these heated exchanges with players and he's basically saying they should've known better. Like, Bruno Guimaraes knows what happened in those situations, but still...
I don't think it's just about Dias being frustrated or Barnes getting away with stuff. There's a bigger issue here – the refs need to be more consistent. And when players are having to question the rules every five minutes, that's not football.