I think it's right that he was called out on it, it was an appalling tackle - although I don't believe it was malicious. Having said that, these things do happen in football from time to time, sometimes you are unlucky enough to be on the receiving end. It's part of the game and you have to get on with it, which I think Van Dijk to his credit seems to be doing. Not saying in any way that he deserves such an injury, but he was certainly dishing it out on Saturday himself.
How to manage JP? That's a difficult one. I can imagine the weekend's events have got to him mentally, would taking him out of the limelight actually make things worse, would he think Carlo has lost all faith in him? But if you keep him in, and his head has gone then the problem could get more serious.
His derby performance was typical Pickford, a couple of truly stunning stops that many other top flight keepers probably would not have been capable of making, and then the inevitable brainfart. Two really, with the VVD incident and then almost gifting them the winner. Got away with both this time. All keepers make mistakes but they are becoming too regular and have been for a while really. I'm not sure whether it's just his part of his character in which case it seems hard to imagine that things will change.
On balance, I'd be inclined to stick with him for now and give him the support he needs, but there has to be a limit, we can't make allowances indefinitely as it will cost us points.