You could debate it, but you'd be wrong. Keeper's aren't infallible remember. Well, not since Van De Sar retired.
I'm pretty sure I can debate it and I wouldn't be wrong (or right). I'd just have a good argument.
Joe Hart is pretty overrated. He's very good yes, but he's still overrated because people don't realise goalkeepers can only do so much, the responsibility of clean sheets lies on the defenders too and City have a great back four. You can't give him all the credit and you can't say he's the best in the league unless you give other keepers equally capable defenders to back him up.