In this case the license was Noncommercial no-derivatives. Wiley, the article's publisher, were obeying the license. Elsevier were not; why was a third party selling (commercially) an article they had no license to sell?
It's possible the authors signed a contract that allowed commercial use by Wiley that somehow extends to Elsevier. (That seems a bit odd since they are competitors, but it's not outside the realm of possibility.) Even if that's the case and it's technically legal, it seems disingenuous to sell the article, since the authors presumably paid a fee to make it freely available to everyone.
It's possible that Wiley received one license while Elsevier received another. Just because one publisher got CC CN ND doesn't mean that's the only license that was ever granted.
Because the work can be multiply-licensed, even potentially by any one of the authors without the consent of the others, you can't really say what "the" (singular controlling) license was without research that excludes all the possibilities. You can only say what "a" license was.
(It's certainly possible Elsevier overstepped its rights… but no one making that allegation has yet supplied enough evidence to be sure that's what happened.)
Then the document they sold should have had the relevant commercial license text included. If the document still contained the CC text then they can't really use that defense can they?
Yes, they can. They don't need to include their license with the work. When you buy a DVD, you don't get a copy of the licensing terms between the authors and the record company, either.
Just because the CC license was included, that doesn't mean Elsevier is distributing the work under it. And in fact, there's a simple explanation: it's a license for the reader.
> How can one verify that a vendor has been licensed to sell a work if they don't include their license with the author?
One generally is not expected to, unless one is the author or author's representative, in which case one doesn't need the vendor to provide the license agreement.
> Maybe a street vendor has been licensed to sell the just-appeared-in-theater movie that they are selling?
A more valid analogy here would be "maybe the multiplex cinema selling movie tickets has been licensed to screen the just-appeared-in-theater movie that they are showing".
