A guy I know gets on his back, ridiculous really. He may not be as solid as I'd like on corners but that will come with experience in the English league. I don't want to get into the whole "if it had been any other keeper" thing but honestly, Hart flaps at crosses and corners every game and we don't hear a peep.
As far as the first Newcastle goal goes, it was a reaction save, he parried the ball away from his net and it just happened to go into the feet of a Newcastle player, there isn't much he could have done about it. I recall a game against Roma in the CL where VDS parried a shot right back at the player and he blasted it back in, it happens. Fair enough, say he could have done better, but it's unfair to put the blame solely at DDG's doorstep because if our defence and midfield did its job a lot of the time, DDG wouldn't be put in these situations.
When called upon DDG largely does a good job and definitely saves us points. His confidence has definitely grown and he is looking more sterdy on crosses and corners than he used to, it's just a matter of time.