Is this just poor QC or workmanship on Rolex's part?

[mikeawesome]

Hello everyone,

So I purchased this 40mm day date about a year ago brand new from a reputable USA AD who has been an AD for many years so there's virtually no chance this is a fake right? There are a few things about it though that make me question Rolex's QC process -

1.) When I went to pick up the watch there was a small hair, maybe 1.0-1.5mm in length that I spotted on the white roman dial. I pointed this out to the sales associate and he took the watch back to their technician who removed the case and got it out

2.) If you look at the photo I attached of the clasp, you can see in the engraving of the Rolex crown that some of the lines on the left side have a black color. Depending on how the light shines on it affects how black the lines are, but that is the only part of the engraving that has a different color from the rest of the yellow gold

3.) On the back of the lug there are 3 small crown engravings and 1 engraving that says Au750. 1 of the crown engravings is immaculate and looks perfect, but the other 2 you can't really tell that it is a crown

Just some of my observations. I might be a little OCD with this, but from all the videos I've watched and people I've talked to, Rolex just doesn't make mistakes like this before the watch leaves the factory.