What threw me was Pep mentioned Caballero's personality, fair play mentioning his build-up play as that is better than Hart's, but the personality part got me thinking.
I have mentioned to a few people that Hart gets too emotional, there's times where you see him hitting himself in the tunnel before the walkout. His brain goes a mile a minute and I think this causes the mistakes he makes, I think he thinks about 5 different scenarios in a space of 5 seconds which causes him to make rash decisions which lead to mistakes.