I have always heard of problems with them on some stupid minor issues in the past and have felt some of the posts were jumping the gun a bit before the issue could have been resolved but your post is well worded, factual and as free of anger as I could hope I would be in your situation.
I am in the parts shopping mode right now and have seen some sites with good prices for parts but seem to be a redirect to Z1 and have felt up in the air about it. Good to know that not much has changed and that if I want hassle free shopping and common courtesy from a vendor I know how to spell C O Z.
If I spend a couple thousand dollars with someone I expect some level of service more than I would with a one time purchase - which a spacer size check would fall into. If a mistake is made I do not expect to be ass-kissed but a simple apology goes a long long way.