I disagree with you here mate about his mental attitude, after that miss v Chelsea he has been far short of his undoubted ability, even in that game alone 5 minutes after the miss he let a pass go completely between his legs and out for a throw in. Against Stoke last week after he chose the wrong option and tried a difficult outside of the foot pass to Aguero instead of just rolling an easier pass to Sane, he sat on the floor with his head in his hands. Things are going for him at the moment but that's when you need to just keep working hard, put it behind and keep going, i think he dwells on the poor stuff tbh.
As for that last minute free kick..................
My thing with KDB is his is an "instinct" player. Put him under pressure and he will pick a pass or whip a cross in or ever shoot. With the position he plays at the moment, he has lots of time on the ball, too much time to think and makes stupid passes. It's like Aguero, brilliant in and around the box when in tight spaces but a different player when he has time to think.