These shots are wonderful! They are definitely up to the standards of the other gurus here, well done!
I think I might tag along on your next POTN meet!
Took that one with the 70-200 and I don't recall ever using the Grad with that lens (although that is what I thought it looked like as well).
Just on this, it looks like faulty jpeg compression. It happens sometimes - you either get missing data, soft compression (like you did) or just black/white fields. As long as it's not on your RAW, you're fine.



