For education purposes, I can tell you the areas you refer to are in relation to long term planning and where the sides will join up to when expanded a few years from now. There's nothing dreadful or lazy about it really, in fact, it's to help avoid design issues which have plagued stadiums such as Old Trafford where the corners don't link in properly with the sides. It might not look pristinely perfect right now, but the design will make the architects and builders jobs a lot easier several years from now and give us a much better final result. To be honest, they're doing a much better job of 'fudging' the corners than they did with the South Stand...