I think it's possible to overthink this. There is nothing really that could be done about that first goal, and without it I don't think County get back into it. With the first goal the momentum went with County. The second goal was of course a horrible error, but how address not making horrible individual errors I'm not sure. The timing of the second goal meant that the momentum had fully swung County's way.
Momentum is difficult to turn around when its against you. There's been a few times in only the past few years we've seen big leads overturned in e.g., two-legged European ties by the best teams in world football (Barca v Liverpool, Man City v Real (2 injury time goals!), Ajax v. Spurs, PSG v. Barca etc.). In each case, the teams were of similar ability on paper and in each case a big lead was squandered. I don't think the likes of Barca, PSG and City lack mentality overall.
But even with the momentum in County's favour, we had a number of chances and decent openings to win the game. It's a shame we never took one of them.