If the nut had been removed from the spindle and then reapplied without grease or any lubricant whatsoever then surely it would appear stiff to remove and hence could lead one to believe that said nut had not been removed at all. Dunno, just saying. Sloppy workmanship if this was the case.
I always grease my spindle. Helps it slide in easier if nothing else. I can't see that adding a bit of chain lube is a problem. Assuming the wheel was off is it up to the tech to clean the thread for you? But hey. We all have different expectations....as has been clearly demonstrated in this thread
It is unlikely that salt could get more than 1mm or more down the thread. I always grease the thread and nut before reinstalling, but that's just my mechanical sympathy in overdrive. Further I always lubricate the chain upon return from a days ride (150-400 miles). Since this is dry PTFE based lub it always looks crap on the OEM chain, as the side plates rust when exposed to atmosphere. Could this be an explanation for at least one of grumbles? By the way my original "change the title" comment was a jokey way to say we've gone off course and that perhaps it could be better worded. Having seen your responses I'm now convinced that you have made a mistake and you should correct the title. LV shouldn't force the change, but instead lock this thread as closed. My concern is that we may not actually hear how the workshop responded when given the opportunity to respond to your concerns.