So the 920 is plagued by QC problems. One good batch, 2 bad ones.
Subsequent communication with Nokia has been fruitless. I started off contacting their support team via Twitter, who asked me to follow the repair process outlined online -- the one where you send in your phone for 2 weeks and (according to many of you) have Nokia just take a can of air and blow the dust out for you. I can't be without my phone that long, so that wasn't gonna work. I wrote to Matt Rothschild, who passed me to the Nokia Care Team, who then told me that the issue was not covered by warranty. I wrote to Stephen Elop, who has not responded or forwarded me along to anybody. So, I decided to fix the thing myself. Here's what I found.
Here in Denmark, Nokia support advice you to return the phone for repair if you have dust in the FFC, they do repair it.
If the remarks of the OP were true, then all Lumia 920 would have dust, but this doesnt happen at all.
In fact there are some millions of phones out there, including mine, that have no dust.
A complex device such as the 920 would no doubt be better made if they kept production in Finland, but obviously Nokia are prepared to sacrifice some of their reputation for quality hardware for bigger profits. I keep saying this. HTC are better at build quality phones and when problems do arise they are very quick to sort them out, on the production line.