All advice and comments are appreciated
I live in Norway so shipping with normal post-office mail isn't an option, they only insure up to 1500 usd. And with insurance and shipping for 6000 usd the price is 200.
I know the guy who sold it to me, and he's a great guy, so I think there is 100% chance this isn't caused by either of us, but something with the lens. The lens is only 10 months old.
And I don't think either of us have even used the focusing ring for any thing else than supporting the lens.
It's just very annoying that the sealing is rubbish on this one. I think it's useless that it could happen without even using it situations where it could be an issue with a non-sealed lens. I have pushed the limit with some of my other gear to see what it could take and they worked flawlessly no matter what. I expect this lens to do the same, that's all.
The AF issue is a "sh!t happens" thing, it could happen, I can accept that. But everybody here would be pretty upset to have it happen to a 6k lens within the first year.
I'll update the thread when I get some kind of feedback from the service place, could be useful for others if it is in fact gravel and it's not covered. That means you can't trust the sealing until the lens breaks and you get it fixed.